exactly...if your lo is still sleepy and ready to fall asleep at bedtime don't worry.
When our lo was almost 6 months, we dropped the catnap because his 7 pm bedtime ended up changing to 8 pm. After taking the catnap away, he was fine. Even now, occasionally, if he wakes before 2:30 pm rather than 3 pm, I will let him catnap in order to keep him happy. However, he usually doesn't even want to!
Cheers!