IsMatch, Match, and MatchAll functions are already supported in PowerApps. Why can't they also be supported in Flow? Here's a simple scenario that is very difficult to do without Regex support.
I'm starting an Approval Flow to be sent to a user's manager. I check a user's manager's mailbox to see if an Out of Office message is set. Such a message will normally include the email address for another person to contact. I want to extract that email and use it to escalate the approval to that other person. I can easily extract that email address using Match(). Doing it without Regex is almost impossible.
Why are these functions supported in PowerApps but not in Flow?