Hi!
Simple & Sinister seems like a great program to follow up a hypertrophy block.
Will it maintain your hypertrophy gains? I think that depends on how much your body needs for hypertrophy and how much you want to maintain. If you are coming off of Mass Made Simple, or a big bodybuilding block, Get ups and swings might not be enough to keep the thighs, chest, back etc at the same level....OR the getups and swings definitely hit almost every muscle group, so it may be enough.
Is there something better? Again, I think. it depends on how you define "better" For a minimalist program that builds strength and hypertrophy, Fabio's Built Strong BTS3 would be a good program..... Pick a push exercise- variation on a bench press, military press or Dips, a pull like Chin ups (you could even do heavy DB KB Cleans) and a squat variation- That may have you "more covered" than swings and get ups.
Geoff Neupert has a bunch of programs that may also fit the bill..... Kettlebell Maximorum or Easy Muscle may be a good fit as well.
Others may have better ideas, but this was just a thought for you!