From Wikipedia, it looks like it's a USSF satellite launched in 2019 with a service life of 14 years. It provides wideband communications to DoD customers.
Disclaimer: this comes from playing a self-made orbital mechanics game, I have no training whatsoever let alone professional experience with this
Speeding up doesn't raise the orbit; it makes it (more) elliptical while still intersecting with the old orbit (shared with neighbouring satellites)- you need at least 2 maneuvers to raise an orbit. You're also assuming a perfectly pro-grade acceleration. In an explosion, different pieces go in different directions, I suspect there is a vector that results in faster speed in the same orbit, but I'm no rocket scientist.
Parts that were sped up have their opposite orbital side raised, parts that got slowed will have their opposite orbital side lowered.
My interest is piqued!
