re: Could MLB vacate Astros title?

No, if you vacate the Astros title the next thing you know the Cardinals will be wanting the 85 World Series title vacated due to Denkinger's blown call then some other team will want a title vacated due to something else or another and you will opening a Pandora's Box for every team to complain about a World Series title needing to be vacated for whatever gets their panties tied in a knot. You can punish and disciple the parties involved via fines and bans but once you start taking away championship titles you will have a Popeye's chicken sandwich like line of grievances being cried about by teams and their fans.