Bottom line: Does anyone know if all cars received a "LAPPED CARS MAY NOW OVERTAKE" message on their steering wheels?

2021 FIA Sporting Regulations.

Article 48 regulates the use of the Safety Cars. Section 48.12, cited in the tweet, is an exception. It is not a standalone rule.

The default rule is 48.8: "With the exception of the cases listed under a) to h) below, no driver may overtake another car on the track, including the safety car, until he passes the Line . . . for the first time after the safety car has returned to the pits." (Emphasis added)

• Exception 48.8a): "If a driver is signalled to do so from the safety car."

• Exception 48.8b): "Under Articles 41.1c), 48.12, 51.6 and 51.12 below."

48.12 is invoked "[i]f the clerk of the course considers it safe to do so, and the message 'LAPPED CARS MAY NOW OVERTAKE' has been sent to all teams Competitors via the official messaging system." 48.12 ¶ 1.

So, IF and ONLY IF all the cars were given the "LAPPED CARS MAY OVERTAKE" message, THEN the requirement kicks in that "any cars that have been lapped by the leader will be required to pass the cars on the lead lap." 48.12 ¶ 1.

If the drivers were not sent that message, but rather were signaled to overtake from the safety car under 48.8a), then there was no requirement that all lapped cars be allowed to pass.