NESN in Boston apparently beat out Bally for stand-alone streaming Red Sox and Bruins games.They've been talking about Bally Sports offering a stand-alone streaming package for Cardinals games for a couple of years now. The impression was it's getting close and there was even a recent story that it's expected to cost about $20/month.
No Cardinals. They pick the five teams with no demand so they can justify not rolling it out for other teams. Somebody is definitely dragging their feet. I think they'll keep the Cardinals exclusively on Spectrum and DirecTV until enough people simply refuse to keep paying those services; then they'll roll out direct-to-customer streaming.

Boston’s NESN Offers Break From Cable Bundle With Streaming Service Launch
NESN 360 will stream live Red Sox and Bruins games, and cost $30 per month.

Boston’s NESN, the regional sports network that televises Red Sox and Bruins games, will be the first RSN to offer its full slate of programming directly to consumers through a streaming service, allowing them to bypass the pay-TV bundle.