Don't know what you put in doubt here.
It's obvious and proven that players with 150 or other high averages playing mobile games (mostly or only) and not ranked rounds, are promoted by level, just like the TP above.
The misfits, are predominately mobile players, and we have at least 5 players, that are masters or lower tiered, and all of which are level 92 plus, one is over the 100 level mark. I can name at least 5 others that are the same,
Probably, they play enough ranked rounds to escape that rule.
This is the complete list of Misfits >L92 who are lower than Legend tier:
"Stri...", Master @L108, has played 8,124 ranked rounds but stays above 63.
"MrN...", Master @L95, is similar. 406 RRs.
"Ben...", TM @L94, has played 843 RRs.
"Sho...", TM @L93, 741 RRs
"BL...", TP @L92, 111 RRs.
Two are a tad different, but their RRs may suffice to escape:
"Gol...", Master @L93, 62 RRs
"MrD...", Master @L93, 65 RRs
There's no indication how these players rose to L93. Stroke play practice rounds, CTTHs or "mobile" games?
You are correct, in saying that the criteria, is for sure secret.
They are undisclosed by WGT, but the community has found out many, if not most of the clues.