Do we know what satellite it will replace? There are quite a few GPS satellites working well beyond their lifetimes by now....
It's being launched into SVN33 / SVN36 orbital slot, those two are very old but far from dead. Likely SVN33 will be paired up with SVN53 and SVN36 with SVN57. The constellation is working with 4 birds over stated requirement (31 vs 27) so they keep moving the older birds around until they start misbehaving seriously and get retired.
Every new launch needs to balance keeping the 24+3 layout while preparing for the next signal event, which now is M-Code / L2C Initial Operations Capability - each orbit with its 3 primary slots with a IIR-M or IIF bird, so those signals can be used without redundancy for basic 3D fixes.
Current status for L2C IOC, including IIF-4:
Orbit A - done
Orbit B - need one more
Orbit C - done
Orbit D - need two more
Orbit E - need two more
Orbit F - need two more
This creates an interesting conundrum, what if the old birds on orbits D,E and F are still fine, the the two IIA birds on orbit A die, each orbit is required to have their 3 primary slots filled plus one backup slot, but it would be down to 3 birds. It might also be possible to bring a retired 'residual' bird back to life, but it was put in residual status because it wasn't keeping up, so it's likely even worse now.
One way that would break the current geometry would be to fill neighboring orbits east and west with 6 birds total and leave the orbits which are ready for IOC with just 3 birds, breaking not only with the 24+3 layout, but with the basic 24 bird layout as well !
After SVN35 was retired, the two worst performing birds left in the constellation are PRN8/SVN38 and PRN9/SVN39 on plane A, but that plane is ready for the upcoming IOC, and they are in a triplet spot with PRN7/SVN48, so they are likely to simply be kept where they are until one die and the other is expected to die inside a year.
What makes 2nd SOPS job easier is birds are being retired due to bad performance, not because they actually died in duty, and bad performance can be detected at least an year ahead.