There were lots of stipulations with PIR when Goodson died as to what had to stay.
As for Match Game and TTTT, I think they thought the MG logo would be a brand that people could relate to...as it turns out, no one really cares and since the shows were NOT MGP anyway, no need to keep it...it was OLD baggage I'm sure.
It was nice to acknowledge him but time to move on...something tells me Mark would cringe what what had his name on it!
John