You had this in game at start – the ability to join on other servers as “guest”.
Imo, the cross-server features you have (and had) implemented are what is truly revolutionary about GW2.
It is not the graphics, it is not the combat, not the skill system or the animations – though these are very good too of course. But other games have nice stuff too and in abundance.
One key thing that GW2 has and (afaik) no one else has as well implemented – is the open world cross server funcionality. Aaand it’s not working…such a shame. It works for dungeons but that’s nothing revolutionary at all, though it’s good that it does ofc.
So my suggestion is – don’t forget to actually implement (or fix) the guest-functionality. It’s one thing that really put you ahead of other devs and made for some awesome community possibilities.