How does this make sense? They would expand their portfolio? How when the Tamron is already for years in market? XD Why would they limit Tamron lenses for other camera mounts? That would be pretty dumb from Sony. They would lost big revenues. The shhties "economic analysys" I read recently, lol. :)) Man, think twice before you write something.
To buy over tamron would reduce Sony competition and expand his market share in Sony own ecosystem.
To buy over tamron and reduce 3rd party lenses availability to Sony competitors like Nikon, Fujifilm etc would make them less attractive.