Clearly the server playerbase has gone downhill. Lots of veterans were banned in the past, such as texas_hitman who is one of the many (just can't remember too many it's been so long). I'm sure they would love to come back on to get some MineRealm nostalgia which would increase the playerbase.
I know the server hasn't been as active lately, there would be no rush to unban everyone, I just hope it will happen eventually sometime before 2020. If this does end up happening at some point, definitely announce it on the forums and I will do my part and tell my irl friends who are banned (supervoo, voocat1, flatcat76) to come back on and have some fun.
I don't think it will be an issue unbanning everyone because most of the major griefers, hackers, etc came on to the server to grief and hack for a short period of time. I doubt they remember the server and probably will never come back on. But banned veterans who do remember the server may check the forums a year from now and be like hey, everyone is unbanned, lemme go play! For example, my irl friend supervoo, did do bad things. He stole a ton of stuff from disbanded realms. But he did that because he was getting bored of MineRealm and didn't care (remember all those old posts of people saying "I'm bored of MineRealm"). But after time passes, people realize they want to revisit Minecraft and that old server they remember called MineRealm, maybe for a little fun for a little while, but that can lead to them sticking with it, which I truly think in the long run would help Minerealm's playerbase a bit.
The other thing is lots of these banned people are too lazy to make a ban appeal, I mean Minecraft 2018, who has time to devote to a ban appeal on Minecraft. But if I go tell them "hey everyone is unbanned from minerealm" they can log in real quick, maybe just play for some nostalgia, but that can lead to them maybe liking it again and maybe sticking to the server for some time.
Also if this did happen I wouldn't expect an explosion of players to be on the server. But maybe when one of those veterans says "hey, I remember minerealm", more and more will join back on over time.
And to add to the part I talked about unbanning everyone being an issue, MineRealm has some of the best staff out there. I am currently afraid to break the vast amount of diamond blocks on my disbanded neighbor's realm because I know staff can detect if I broke blocks that weren't placed by me. If for some reason a returning player said "screw it, I'm unbanned, I'm back on, I'm just gonna grief and leave", they could get banned by the staff, and I'm sure there's a way staff can revert any griefed buildings back to their original state.
I don't care if you come back to this poll a year later and still no unbanning has been done. It is never too late to unban everyone.