That's what I refer to by battery issues. If the entire LCD display is turning on when you get a notification, and like most of us, that's a lot, you will have issues with the battery not lasting nearly as long as before. Compared to AMOLED where you don't have that problem.
AMOLED is an improvement in that respect, but, again, it doesn't mean LCD causes issues (as issues are basically synonymous with problems). It's a different technology and uses some more battery power for display purposes, but it doesn't mean it's an actual problem of some sort.