I fully expect that to happen. And it will be Lori Loughlin, a CGI Lori Loughlin.
See! My idea is catching on.
It's the perfect cameo.
I wonder if we'll ever see Future Ted as played by Bob Saget. They showed us Future Robin, Future Lily, and Future Marshall all played by themselves, so probably not.
Also, the episode with Mike Tyson showed Future Lily and Future Robin "18 Years in the future" which is contemporary with the time Future Ted is telling the story to his kids.