I guess the Community center reverts to the Joja warehouse so it stops the bundles from working and therefore forfeit some rewards, BUT you can afterwards buy the stuff you're missing like the bus, the minecarts, the bridge repairs, greenhouse etc etc.
here's some comments from a reddit post "It's possible to complete all the Community center bundles, then run over and buy a joja membership before the Community center opening ceremony, and then get the Joja Achievements instead. " from this thread "
https://www.reddit.com/r/StardewVal..._happens_if_i_buy_the_joja_membership_midway/ "
If this is your 1st playthrough its better if you do the community center just for the cutscenes etc and to be fair the challenges, but the joja warhouse, instead of crops, items and stuff gathering you can just buy everything with money. Both ways are good in their own way so its only up to you and how you want to play the game! Hope it helps!