I’m still hoping for a June 29th, 2021 release date for D2: R, but this is probably how it will play out, or at least closely:
Chains of Domination release: End of May
TBC Classic release: Mid June(The WoW releases might be vice versa, etc., or may release later depending on their current beta testing)
D2: R beta: End of May to Beginning of June
D2 Ladder Reset: Beginning of June(gives some time for players to play og D2 Ladder before D2: R release)
D3 Season 23 ends: Between End of June to End of July
D2: R release: Some time during the end date of D3 season(End of June to End of July)
D: I release: September