No it is not. Never have we seen hagoromo as juubi jin. By seen i mean like real scans of it
Yet we have statements from Hagoromo himself saying that he was the Jin.
BZ changed the tablet so madara's or obito's statements are null.
Ok.
What hago said depends on translation.
Hagoromo could evel be lying for all we know.
Why hasnt he fought madara or kaguya?
Not really. There is no translation you can find that'll take "We sealed the Juubi inside myself" or "I broke up the Juubi inside me into parts and named them" and completely change their meanings.
That's the only explanation, but then again. Really? Why would he lie? He has no reason to. Hagoromo has also made it pretty clear that he couldn't interact with the outside world until now, so I dunno why you are asking why he hasn't fought Kaguya or Madara.
New manga facts>old ones, its a general rule.
Solid scans of hago sealing kaguya > possible mistranslated statement of his.
1. Don't know who told you that is how it works, but it isn't. Especially when there is more evidence on the side of the old manga facts.
2. There is no scan showing Juubi/Kaguya being sealed in the moon by Hagoromo and Hamura. Only a scan showing them initiating the seal, you don't know what happened after that, but Hagoromo made it pretty clear that they sealed it inside of him.