Yeah, the best way to handle this is with a version in the path and then the host can knowingly/willingly upgrade the library version and SRI hash at the same time.
SRI is good for use with a CDN, where the same entity controls both the HTML that references the JS and the JS being referenced. In that case it keeps someone who subverts the CDN from being able to XSS the site.
(I used to make web server software)
If I was the mean person at IBM that buys startups and makes them "right", it's a lot more work to fix terrible added to terrible than plain terrible. And my last startup got bought by IBM, so I've experienced that pain personally.