Microsoft seems to constantly be looking for feedback from users in regards to their experience with the company's products and services, as evidenced by the various Insider programs it's running. In addition to that, Microsoft has recently been asking users to engage in direct conversations with the team in regards to specific features, and today, it did the same for the Alt-Tab shortcut.
Windows 10 users - regardless of whether they're running an Insider build - have received notifications asking them to access a webpage to talk to the development team on a call. Though the call sessions seem to have ended for today, Microsoft is hosting a live meeting tomorrow, March 12, from 9:30 to 11:30AM Pacific Time.
The web page doesn't clearly specify what the purpose of the call is, but it seems Microsoft is trying to learn about how users utilize the Alt-Tab shortcut to switch between windows in the operating system. This experience has largely been unchanged for years, with most of the focus being on the Win-Tab shortcut, which brings up the task view and, more recently, the Timeline.
If you'd like to join in tomorrow's meeting, you can head to the respective page to talk to the company.