This is common practice by retiring SCOTUS justices. Happens all the time in the private sector as well.
What I don’t like are the rumors Juan McCain’s wife will replace him.
Mccain came out in support of Kavanaugh. Not necessarily a bad thing, in this case. Even if he is establishment, he is known to be a strict constitutionalist. Even if he follows Kennedy faithfully, Kennedy was right leaning much of the time, and Trump will get at least 2 more nominees -— Thomas is anxious to retire, and I wouldn’t be surprised if he announces that as soon as Kavanaugh is confirmed, unless it is determined it would be better to wait til after the midterms. Plus, RBG can’t last much longer, so there’s another one. (She may even be forced to quit, because she has been found to say she doesn’t think the Constitution matters.)