@DeepInTheHeartofTexas answered well already, but I’ll add a couple more thoughts.
People seem to fear Disney without FastPasses. Now, of course, I’m actually anti-FastPass myself. Never liked them. But regardless of that, life without FastPass at Disney has actually been great during this time period. Standby waits have been consistently and dramatically lower in most cases than pre-COVID times. Part of this is due to COVID…and part of this is because FastPasses are not being used. (Fastpasses make Standby lines significantly longer.) So, don’t be scared of Disney without Fastpasses. Overall, we found it actually made touring Disney easier without them.
I don’t recall any single rider lines being open because they are keeping parties separated…not sure that is changed in the last couple months, but they weren’t open as of December, when were there last.
As already stated, EMH will NOT be returning. Instead, they are eventually switching to an Early Entry program that gives on-site guests entry to ANY of the four parks each day. To date, this new program isn’t in place, and EVERYONE (both on-site and off-site) have been able to get into the parks as much as roughly 45 minutes early.