@soxfan23 is correct, if you have YouTube TV you have access to ESPN streaming.
At times ESPN referred to it's streaming as ESPN3 but now it is mostly referred to as the ESPN App. Within the app you have access to all games that ESPN is streaming for free via the Watch link. Also available in the app is the link for ESPN+ which requires a separate subscription. I have it via a Disney+ package.
But I think the main thing here is that ESPN will not be streaming any UConn games that are not being televised by one of the ESPN channels. The SNY out of market streaming will be via the Fox Sports app/service.