I mean like, if we're going to assume canon is just "what happened in the TLK universe" then TLG will be canon.
But like there are several types of canon in this fandom, not including finer points there are like:
1) First Movie Purists: Only TLK1 is canon, not SP, not 1.5, nothing else. A subset of these would probably be people who consider the first movie and say Chronicles of the Pride Lands to be canon, since it was based entirely on TLK1.
2) TLK6NA Purists: Only TLK1 and 6NA are canon, Kiara isn't real and SP never happened. I've seen a few of these and they're generally considered unreasonable as far as I can tell.
3) TLK & SP Purists: Only TLK1 and SP are canon, Kopa never existed. These are fairly common, and to be honest this is the most logically "canon" out of each of the types, since movies override all other media (or at least they would in other fandoms). This is the most "official" but it still isn't; its not an officially declared canon but this is what the filmmakers of SP and the creators of TLG probably considered what happened.
4) Consolidators: What I call people who make up theories so that Kopa can exist and still keep the SP timeline. Also common (I am one of them), although they are sometimes frowned upon because of the TLK fandom's general dislike of fan theories that don't have mountains of evidence.
And of course each type has reasons to both include and exclude comic characters e.g. Tojo or Malka. Also there are a lot of canon conflicts around 6NA because of the Scar origin story as well.
But like when it comes to TLG people will consider it canon or not-canon based mostly on their personal impression of the show UP UNTIL it gets involved in a doctrinal conflict. It already is somewhat in that Kion is "second-born" because Kopa doesn't exist to the creators, but expect the real fight to come if the show ever covers say how Scar got his scar.
But like if you're asking if TLG is canon it depends on what you mean. The creators of TLG will almost certainly consider it to be so, but then the actual people who have worked on each film (not including VAs) are probably not actually shared that much.