The implication is that, just as 身 勝 手 の 極 意 / Migatte no Goku'i plays with the fact that 身 勝 手 / migatte / “selfish” literally means a body acting on its own, the term 我 儘 / waga- mama (another term for "selfish") is used for its literal meaning of "as the ego (desires)" And that presumably connects somehow to Vegeta's trick of getting stronger the higher his fighting spirit gets, or some other new trick he has. Perhaps the idea is that your power follows your will, reflecting stronger fighting spirit = stronger power.
The 極 意 / goku’i part is the same as Migatte no Goku’i and, as before, it means the secret of mastery for some skills (not just an ordinary secret) And with Migatte no Goku’i being used as "Ultra Instinct", presumably it already has an official English name in line with what is likely to be quite different from any literal translation. We can say that the main difference between Goku's and Vegeta's divine techniques is that, even though both names mean "selfish", Goku's name is due to the physical body (身) and Vegeta's is due to the mental (我). And presumably the nature of Vegeta's technique expresses this difference.
More SPOILERS.
We also have the new page, VEGETA threatens to destroy Granolah's home planet with a HAKAI, and this ends up awakening the true power of Granolah and Vegeta appears to be finished, losing at best.
And to clarify a few things for some people DAISHINKAN does not belong to the 7(seventh universe), and he was cited as someone that Goku needs to go through, the statement that Broly, Bills, Whis, Daishinkan, are superior to GOKU is largely, it is general and not limited to the seventh universe only, otherwise the daishinkan would not be mentioned.
So, if you deep down think that JIREN wasn't mentioned because it's part of another universe, you're wrong. Native Japanese confirmed that when UCHIDA (who is more relevant than you) mentioned Broly, Toyo nodded and did not refute or disagree with UCHIDA's speech to his editor who is helping him.