The grammar would. You could probably easily "degender" Arabic by just making everything masculine, but you would have to pick one to be the one gender, it can't be neither. But you'd also have to invent a bunch of new words, or just declare that things with "real gender" is all gender neutral in its masculine form now. Brother is sibling and we won't have a word for brother.

Similarly in most Latin languages removing the gender totally would leave open questions of how grammar works. You'd have to decide formally how to do even basic stuff like pluralize which is now done according to gender. You COULD probably just decide you're going to use one of the genders, but it would require reworking the language from the bottom up.