Links from xyz.wordpress.com and abc.wordpress.com are 2 different links from 2 domains. Not one of them has the "DA" of www.wordpress.com because thats also a different domain.
We can say, that google is seeing it that way and not. Not because, in search console linking domain would be "wordpress.com". Noretheless they are different in a lot of points, DA is the most important one.
If you get more links from the same domain, it makes them less and less important (for every new link, not the old links). In my tests (wordpress & blogspot) it was the case, that it was less and less for the one linking subdomain, not all the sub-domains. Somehow understandable? So the answer is "it depends" The test is not 100 % accurate and hard to compare but seems like thats the way it is.
What I also realized, when I get high increase in organic traffic and I have done nothing and no update was going on, it is mostly one new organic link. You can build links as much as you want but organic links beat everything and I dont know how google can figure that out so clearly.
So when you have a good amount of links, you should focus on your user. Like I do, thatswhy I cant tell you how MOZ or any other Tool is handling it, I simply do not care that much.
One of my former competitors has 10 times more Links as we have and today I call him "former" competitor. Former because we reached a new level, he not. We have now 9times more organic traffic and he still stuck where he is since a year. Well we have a single Page with more monthly organic visitors than his domain. We started on the same level 1.5 years ago. I did not build one single link, I just focus on users. A lot users, talking about hundrethousands organic visitors, for germany in this niche a lot. Ok we are now going into other topics, but thats not the point here.
All these topics are finance topics so maybe a YMYL special thing, but I have some more domains wich work better and better without building links and non-YMYL topics. But there is a lot great content wich makes the domains earn links. At least you need an entry, a dooropener to get links coming in.
Woop - to much hah So you are somehow right, but dont think to much link Anyway - Good Luck!