Ive made a post on the subject of Of Gods and Men and Renegades and if the fact original cast is taking part, does that make it canon.
I can very much see why some people would call it canon, but for me its only really the copyright holder who can make that call. In an ideal world, it would be the person who created the show, but the show as made for a TV channel, and Gene Roddenberry has obviously died, so like or not a business owns Star Trek and can say what is and isnt canon.
Actors are a big part of any show, but they are not the be all and end of of it, some actors will have a genuine love for the franchise they are in, but not all of them.
TBH its the Of Gods and Men type productions which I thought would get "fan films" in trouble, its very easy to confuse a production like that for something official, even more so than a Star Trek Continues, which for all its high quality, is not built around original cast members, sure it had Apollo, but that was one episode. Chris Doohan is also just the son of James Doohan so cant really be counted.