Ubisoft recently released the Match Replay system in Rainbow Six: Siege so that players can re-watch the games they have played using a variety of spectator tools. But, Ubisoft hasn't stopped there, as it recently also announced that professional Rainbow Six Siege games are becoming available on the system, with the recent Six Invitational being the first to get that treatment.
The system will bundle days of play together so that viewers can easily download and watch the replays. Each bundle is expected to be quite meaty in file size, especially for the Six Invitational, which can reach up to 8GBs for a single bundle.
Ubisoft is also planning to add more match replays in the future for regional leagues and other Majors, but it has not yet put a time frame on when they will be arriving - hopefully soon after each game actually takes place.
You can download the replays for the SI2021 here.