Been playing a survival game since 18w50a and now converted to 19w02a since day of that snapshot release. I have enchanted many many items on the crafting table without noticing anything a-typical.

Today I did a level 3 enchant requiring 30 levels on a diamond helmet and I got both Projectile Protection 4 and Fire Protection 3 on the helmet. From past experience and lack of comment on the release notes, I assume all forms of protection are intended to be mutually exclusive.

Mac OSX 10.12.6, Java version 1.8.0_171