Note: "guys" is typically a gender-neutral term in colloquial U.S. usage (def 1b: https://www.merriam-webster.com/dictionary/guy). It probably took on that meaning because people in the U.S. lacked another term of equivalent informality. (Tone-setting is important, even in languages where you don't have a strong formal/informal distinction.)

However, "mates" in British/Australian English were traditionally assumed to be male, and though this implication has weakened somewhat, it is still more the case than with "guys" in U.S. English.

So, oddly, taking international usage into account, you're kind of advocating for dropping a more gender-neutral term in favor of a more strongly gendered one. (Nobody is going to say "cohort mates"--that's too clunky.)