upgrades

I would. Here's a scenario... all of a sudden you develop severe troubles with your MacBook and it's deemed that it needs to be replaced. You put back in the original stuff. The bad MB goes back with the original parts. You get your replacement MB. You can re-upgrade with your upgrade stuff.

Needless to say, this probably won't happen but it could.

You could also get an enclosure for the original drive and use it for backups.

-GDF

 

True. If the OP meant in order not to void his/her warranty, then no, you won't need to swap them for that reason.