this 737BBJ popped up tonight and I looked at its history

Aviation Notable Activity
1

flightaware.com/live/flight/N457 … /KTUL/KTUL

Long flight for a 737
Probably having a new interior built in Tulsa.

2

Another 9 hour flight today Tulsa to Tulsa. What they heck are they doing?

3

Living on Tulsa Time…

4

Just like you said, probably a new interior. Most likely these are “cold soak” flights to make sure everything is up to par.