If you wanted a MLB stadium at that site, that ship sailed a couple of decades ago (or are there people who still think that Portland being used as a "competitive bid" to sweeten the deal for Montreal's move to Washington was actually a real opportunity? Please.).  While there was a strange plan to retrofit the stadium for baseball only (was never going to be multi use, it would have been terrible for soccer or football and WAS terrible for soccer before this renovation).

If we ever get a baseball team, a new stadium which was purpose built for baseball would be most appropriate, not a rectangular sports field which just wasn't finished on one side for 80 years.  Multipurpose stadiums just meant they were terrible for everyone and for that reason we stopped building them in the 60s.