Caveat: The last posts mix up "at TL stage" with "to reach TL stage".
These things become complicated and may twist our minds due to special rules for the time of the new tiers' implementation for those who were in the formerly highest tier then.
Again, I cross out numbers which aren't valid currently.
Before TL tier, Legends would saturate at 400 rounds. To reach the new TL tier, each saturated L had to play 100 extra rounds.
Now, L saturation is at a total of 500 L rounds, 60.000 average to advance to TL
Before C tier, Tour Legends had 500 rounds to saturate. With the advent of C tier, their averages would jump up because they were robbed of their 300 best rounds. Then, they had to play 200 additional rounds to saturate. This is the source of the phrase which I have been objecting to.
Now, TL saturation is at a total of 200 TL rounds, 59.00 average to advance to C.
Saturation for Champions is at 200 C rounds, as stated by the mod.
Addendum: There's no conditions to become a TC because this is only by WGT's appointment. They've only awarded this in two special cases, as stated above. Otherwise, it's blocked, another carrot(?) They also said that there are no plans to change this.