We made the call not to work on link preview on the mobile web (or hovercards on desktop web [1]) in the remainder of Q2 based on our earlier analysis. I am tempted to say that this secondary analysis justifies implementing link preview on the web, but think it is at least worth a discussion for mobile web, due to the potential trade-off. Do we try again in Q3? I know Florian is already doing a great deal of the work.
I'm interested in doing it as part of the speed arena. In addition to the apparent lift with the other metric, for users who don't go to the next page, it saves a lot of bandwidth and is very fast. There is the drawback that some users may really hate it even when most users appreciate it (even if unknowingly) - it seems like an obvious opt out could address that case.