It seems that tightening up the requirements for team matches is not a high priority. One fairly easy way to exclude members with not-yet-settled ratings would be for chess.com to introduce the MINIMUM NUMBER OF GAMES option that is available when creating tournaments.
Whether any Team Admin would use it though, is another matter. It would have to apply to BOTH TEAMS in much the same way as these other Team Match balancing mechanisms (STRONGEST EARLIEST BEST MATCH FAIR MATCH WEAKEST ) I proposed earlier (team-matches---level-playing-field-scheme and first-come-first-served-team-chess).
Could an unfavourable result in Team Matches be appealed if it was due to the presence of several new members provisionally rated as "1200 newbies" who turned out to be in fact highly experienced players? If interested please see current match Scotland v Bulgaria and look at the ensuing ratings at foot of the entrants' table for a possible example.