If it ain't broke, don't fix it.
The pump is likely plugged into a single receptacle on a dedicated circuit, because there used to be an exception in the code that allowed a setup like that to avoid GFCI protection. It's possible that the pump will not play well with the GFCI, and then you'll be up shits creek (literally).
It's quite possible that the other pump was originally installed this way too, but then somebody needed an additional receptacle in that area. This person likely didn't understand what was going on, and swapped out the single receptacle for a duplex. Or all this equipment was installed before code required GFCI protection.
Newer pumps should be designed to work with GFCI protection. If you ever update the pump, you should be able to switch to a GFCI then. For now, I'd leave it as is.
If you're worried about flooding due to a power outage, you could install a backup water powered sump. Or better yet, get a generator.