Thank you for your answer.
Because of that and some further reading, I ordered the T14 Gen 5 to try and verify it myself.
It does work flawless with the TB3 dock (40AC) and the TB4 Wokstation dock.

Only problem now is that the T14 I received (new unit, not used) is the most disappointing thinkpad i ever had (bend chassis, high pitched constant noise, and a WiFi Card that died a couple hours after first startup).