It's been a long time since I've delved into home theater. Now that I'm retired I'll have more time to enjoy my system. Considering updating my AVR. Right now I'm using a Marantz 7008 driving Def Tech BP2000's with 7.1 in ceiling surrounds (don't remember what brand). I don't mind spending the money if it makes sense to update. I'm a bit rusty with what's out there now so bear with me. Thanks.
As mentioned, if the new movie updates, 4k, atmos, etc. are appealing to you...you will need to update the avr. In ceiling surrounds are not the most functional in a good surround system, but they make great atmos speakers so something to think about there.
Subs...idk where you are with a sub, but the newer subs are great musically and still great for movies...if you don't have one, this is an upgrade I would consider.
Speakers...the life blood of any audio system. Not that you should get new speakers, but if you've had them more than 10 yrs...I would demo some that may be a step or two up over the ones you have and see if it means anything to you.