The mcmeta file used to provide the "blur" property to the enchantment glint is no longer applied due to an incorrect name:
The textures are called enchanted_glint_entity.png and enchanted_glint_item.png, while the mcmeta file is called enchanted_item_glint.png.mcmeta, this makes it not apply.
The mcmeta file should be cloned, and the files should be named enchanted_glint_entity.png.mcmeta and enchanted_glint_item.png.mcmeta in order to apply the blur once again.
can confirm in 1.20-pre7, attached screenshot demonstrating the issue (note the difference in file names)