I propose that LL should consider building a completely new and larger version of Orientation Island inside SL, but instead of one single small island, an archipelago of NINE island sims, teaching new Residents all the skills needed to use SL properly, but done so in a fun, easy, memorable, enjoyable and rewarding game-like way.
Completing all of the new Orientation Islands tutorials should be made a new Resident requirement needed to exit from Orientation Islands into the wider Second Life world.
I myself went through such a qualification process in June 2008 and it helped me enormously, I've never needed any further help with the viewer since. But that 2008 model of Orientation Island sadly no longer exists. (But a video of this Orientation Island does, at https://www.youtube.com/watch?v=ocGSDSw2Xs8 )
Direct teleporting out of Orientation Islands without completing all the tasks should be made impossible. This might also might prevent unwelcome AI-generated Bots from further interference with mainland and it's population too.
A free basic AO should also be offered at the start "Arrivals Island" section of the tutorial to give new Residents a better more realistic movement. It could also act as a skill in unboxing, Inventory handling and wearing/attaching items such as AO HUDs.
Also include an Orientation Islands Skills HUD which keeps a record of the new Resident's tasks and skills progress and times, which when all completed and reaching the required standard, would permit a qualified new Resident access to SL's Mainland.
Orientation Islands tutorial should be split up into an archipelago of NINE separately themed island sims (possibly arranged in a 3x3 grid?), all linked by bridges (automated trains, or ferry boats!) teaching all catagories of skills in specialised island sims, all of which are large enough to handle dozens of new Residents at a single time....
Arrivals Island - Explaining what SL is, it's rules and how to qualify for entry into Mainland.
Movement Island - Teaching all the movements needed to control your avatar.
Communication Island - Teaching how to communicate directly and indirectly.
Navigation Island - Teaching Maps, Landmarks and layout of SL's continents.
Vehicles Island - Teaching how to use land, sea and air vehicles.
Creators Island. - A sandbox tutorial area demonstrating prims, meshes and scripts.
Shopping Island - Freebie clothes, SL Marketplace, L$ currency tutorials.
Homes Island - Linden Homes vs Mainland Homes vs Private Islands Homes tutorial.
Departures Island - The final area in Orientation Islands, where a new Residents Skills HUD, containing all the skills and tasks data they've achieved (or not achieved) are read by a reader which decides whether they've qualified to leave Orientation Islands and move into SL's Mainland - or not!
Departures Island should allow new candidate Residents who have not reached required skill/task levels to return to certain areas to redo that task or skill again.
Perhaps a timer and leaderboard screen could record the times taken to achieve individual Orientation Islands tasks? Make the times tasks and skills gained the basis for entry to Mainland.
After all the required Orientation Islands tutorial tasks have been completed, reward the newly qualified Resident with a t-shirt or hat marked with something that reads like "I'm New!", "I Just Qualified For SL!", "Don't Call Me A Noob!" etc. Also include a Landmark to the Welcome Hub.
Perhaps a large Rules sign should be read and acknowledged with a click.
A one-way (never to return) portal into the "real" SL should then be made accessible, teleporting the newly qualified Resident to an Infohub on the mainland to begin their Second Life....
Make all of this feel like a fun game which encourages competitiveness, rather than a boring chore that people would rather skip through. New Residents could compete with each other for a "Best Time" or "High Score" displayed at the individual areas on large screens where future new Residents could measure or compare their skills against.
The Orientation Islands tutorial should be multilingual too, including all nine of the languages currently available in the main Second Life website. Classic items like the Beach Ball, Torch and Chat Parrot should be included in the Orientation Islands tutorial.
The Welcome Hub should be retained and repurposed as a place where new and old Residents can visit for further help and advice from experienced long-term resident mentors.
Perhaps a duplicate copy of Orientation Islands could be made available to the Portal Park Hub, so older experienced people can "play" Orientation Islands for the nostalgia, or just for fun and possibly re-learn lost or forgotten skills too? The same tutorial could retain it's timer-based system, but instead of needlessly requalifying for the mainland again, it could instead reward Residents with a small L$ payment like in other games such as Linden Realms.