They did the same thing when they dropped Brendon Hartley at the end of 2019. It was not until Honda issued their own public thankyou to Brendon for his contribution (he had helped them a lot with energy recovery work) that Toro Rosso finally issued a mealy-mouthed thankyou.

What a disgrace! They need a good PR manager. It baffles me how they manage to make fun social media posts, but cannot handle any situation with dignity. Probably something they lack as a whole. Should've announced the departure before the race, should've made a normal post. Should've taken a pause.