Daniel Ricciardo has now been officially confirmed as a McLaren driver for the 2021 F1 season. The Australian driver is therefore leaving Renault and heading to a team powered by Mercedes engines. This news wasn't a huge surprise, as rumors and statements had been growing increasingly clear, and the official announcement was finally made today. Consequently, Carlos Sainz's new seat will also be officially announced, though I don't think he'll be returning to Renault in a swap deal.
If Carlos Sainz has decided to leave McLaren, it's because he's found a better seat. And that seat is already known to be at Ferrari. Only an official announcement is missing, but it could be imminent. Therefore, bombshells are dropping that shatter the apparent tranquility brought about by the coronavirus during this sporting hiatus. Formula 1 fans already have something to look forward to these days, because several pieces are going to move. Vettel's move has already happened , now Ricciardo's, next will be Sainz's, and who knows if there's another one bearing Alonso's name…

McLaren (with Seidl and Brown) has expressed satisfaction with Daniel Ricciardo's arrival at the team. And of course, given Renault 's recent struggles, it was also a relief for Ricciardo himself to see that he's joining a team on the road to recovery, one that will be competitive with the Mercedes engine they're using, and where he'll have the opportunity to achieve better results. Furthermore, they believe he'll bring new qualities to the team.
However, Seidl and Brown also had kind words for Carlos Sainz . They said he contributed key elements to McLaren's recovery and did an excellent job. They also wished him the best of luck in his new endeavor.