I have been thinking about that too, because Kyle Katarn is one of my favorite Star Wars characters hands down. I think he certainly could fit as a freelance agent who gave them information on the second Death Star, leading the Alliance to send the Bothans, while Kyle heads out on the next job. I wouldn't mind him stumbling upon the initial Dark Trooper project (the phase ones and maybe attempting to stop them before they wipe out a village due to the Imperial crack down on Rebels.I was about to object and say the character has been made redundant with Rogue One, then I realised they could just bump his story over to whatever covert mission got them the skinny on the second Death Star. Of course this also renders any potential Dash Rendar inclusion redundant. Win-win!
Or something like that.