After 15 to 20 years of 64bit supporting systems being sold, I don't think it's an issue to drop 32bit support. Even if someone wants to use such an old pc for any reason, it should be fine to run an older version of Minecraft. There's still MC 1.8 servers around, and they'll likely continue to exist for many years to come.
I remember playing the original java 8 version of this game back in 2011 when it was freely distributed. I was 17/18 at the time so felt I was slightly too old for it but I do remember the sensation of playing something which felt completely novel.
Kind of crazy how much gaming has changed since then while minecraft remains a java executable.
It wasn't a little kids game until years later. Also I think it's old enough that the early versions were actually Java 6... I remember updating my code for Java 7.