She seems to really sever no purpose on her own, let’s look at what she does in Shadowlands.
SL beginning
In the beginning of 9.0 she is there with the other leaders and then jumps into the portal to shadowlands and then disappears from the game for the leveling experience and then appears briefly in the max level Ardenweld campaign for one quest and then disappears again.
Ardenweld Campaign
I’ve seen people say the Ardenweld campaign is 1/3rd about Tyrande, but it’s actually about the night warrior power itself, not really about Tyrande, sure Shandis is concerned about Tyrande and we want to get rid of it, but we don’t delve into Tyrande as a character we are just concerned with this power that has been used in other places in the universe. We do a bunch of things to try to understand the night warrior power but everything we actually do in the Ardenweld campaign for the night warrior power essentially amounts to nothing as of 9.1.
Sylvanas vs Tyrande Cinematic
9.1 Tyrande just appears in Ardenweld to fight sylvanas to a stalemate until Sylvanas runs away after Anduin gets the sigil because Sylvanas was just the distraction, Tyrande flies up and chokes sylvanas until she gets depowered. Nothing stating Sylvanas couldn’t have just smoked out before Tyrande got depowered either (as sylvanas just smokes out afterwards) and Tyrande needs to be saved by Ysera.
Elune Cineamtic
Then we have the Elune cinematic where Elune just takes control of a dying Tyrande and talks to her sister. Here you could say Tyrande’s main purpose was to be a communication device for Elune so she could talk to her sister, or a delivery mechanism for the tear of elune. Then Tyrande wakes up and she has different colored eyes.
We don’t get any internal reflection on her character, we don’t know what was said to her that had her change her mind so abruptly, she doesn’t even really seem to know what Elune said to her. Now juxtapose that with the Sylvanas/Uther cinematic where Sylvanas talks about her feeling and then wakes up, we entirely skip all that with Tyrande and it’s just Tyrande changing her mind.
This is kind of where Tyrande’s story ends in 9.1 so far, she is absent again for the rest of the patch, until the sigil is create but then she does nothing anyway and is just kind of standing there.
What was the point of the Ardenweald NW campaign?
So what did everything we do with learning about the night warrior and searching for Tyrande even do? Nothing, it seems to have been a dropped idea from 9.0. We don’t help Tyrande, we don’t even find Tyrande. Tyrande just randomly shows up to fight Sylvanas in 9.1 and then Elune controls the power for Tyrande by either letting her controlling it or taking most of the power away so it won’t kill her, who knows, it’s not explained. So essentially everything we do in regards to the night warrior in 9.0 was pointless. The night warrior power seems to have been shown to be pointless and not actually effective at doing anything. The deer used it to kill an old god, Tyrande used it to do nothing.
Tyrande in 9.2
So far as of the defeat of Zovaal, Tyrande is also absent from 9.2. She will show up for the judgement of Sylvanas, but so far she is entirely absent. Shandris has like one stealth quest in ZM and then just stands around in the home base.
Conclusion
So what was the point of Tyrande in Shadowlands? Other than to be another character that is thrown under the bus for Sylvanas’s story by being the night elf representation that “forgives” Sylvanas for genocide in 9.2 (or 9.2.5) in the form of some menial task for her to complete so they can forget about Teldrassil entirely going forward, because as they said in 8.1 “Tyrande got her revenge for night elves”.