Lowkey yes
A bit longer version he is afraid that being s class isn't what makes a monster and if even the worst monster (shj) can change and be more human that mean that he alone is the only monster. He is afraid that when every other sclass (monstrs) will change bc of hyj and he'll be left behind being the only one being a monster and the root of what makes them "monsters" isn't the powers and they can change. He doesn't belive one can change/stop being a monster since it's something he believed since he was a kid but now seeing them changing he no longer can claim to be better then them just bc he wants to protect normal people since he still thinks of himself as a monster but starts seeing humanity in other sclass

Wait so he’s basically getting fomo? :(