Some people's long careers that switch between being KoS, SoHM and FK and possibly many more I think should be reminding us all that generally people do accept others making new choices and taking new paths instead of thinking "nah they didn't change paths they want our power, they were traitors of their previous guild and they want to avoid RP".
An application saying "oh I tried magic and I saw how dangerous it is I want to join KoS now" is a cliche bathroom thought for meta-constructing your way towards your new guild, or kid-level "RP". It is practically equal to "hey I'd like to join, wanna meet?" in my view, but with annoying pleasantries which offer nothing to either party and can only mean a rejection if the guild arbitrarily decides the pleasantrism wasn't good enough.
If we were going to be annoying about it, we could also not understand that the race-changed Bob in front of us is the same Bob we knew. We would think our friend Bob is lost and never find them again, or maybe that dwarf sitting in front of us stalked them, learned about them so that they can pretend they are them and killed them. I wonder what would happen when Bob showed up AGAIN, we go crazy, probably retiring our character?
Lots of loopholes. It's possible that RP is dead or is just in another building (probably an RP-enforced one)
OR
We can just accept some things and RP our way through the rest
P.S. Talking about RP *in* guilds as I am... We can try to seriously scrutinize guildmates for their behaviour, kick them if they have grown unworthy of their position beside us or ask for their deposition. See how that goes, that would be fun. You inspired me, people. Thank you.