According to Aryan's post in Zaiba's link above: No.
Since gang bases are not an official institution anymore like nightmare said, admins won't be modifying houses according to the clan status anymore, means if the clan tolerates it there shouldn't be problems. But, in case the MM members want their base houses to stay clan exclusive, they can probably report you to any manager and get your house removed without refunds - even if they don't currently have members who are going to buy it. Chances are the empty house then will be completely deleted to prevent this deprecated loophole from occurring again.
If you want my advice: it is definitely safer to not buy a house in a gang base.