One common thing is that alot of people forget,misunderstsod or simply diden't think about two major things. (Note, apologize for grammar ahead of time.)
Those things are, first and mostly that the 5 year plan is counted from the launch date of Destiny 2. hence 5 years of destiny 2 is the road map currently. That ends in september 2022. Silly enough alot of people get this wrong so this is just an [b]FYI[/b]. This means by itself little tho but it will add up later.
The second thing is that Destiny 3 has allready been in development with Activision since 2018 or even earlier like late 2017 based on anonthenine. There was even ment to be a Destiny 4 based on the contract with Activision. Now however the IP and what to do with Destiny is litrally all up to Bungie. That for now did lead to a Year 5 road map ahead.
But! There is also a third thing! Phil Spencer said in an interview that all games on the xbox platform will run on all xbox one series for one year. After that it will be next gen only. Meaning because Sony is less harsher with what hardware games run on, this will quite litrally be where the bottleneck for games will change as they don't need to run on Xbox one any longer. 2020 holiday is the release date of the consoles and then add a year, you get Q4 2021.
That's very juicy because Bungie nearly allways release mayor content DLC's in september aswell as the main vanilla game's. So theoretically what year would be the earliest year for Bungie to release Destiny 3 if they wish to have it next gen only? 2022 September. What year does the road map end? 2022 September.
This is it. I want to end with this qoute from interview 44 days ago.
[b]Bungie isn’t done just yet with its plan for Destiny 2 updates, but it seems the developer is already thinking about Destiny 3 – it’s just not ready to share any details quite yet. In an interview with PCGamesN, the studio’s comms director, David ‘DeeJ’ Dague, says we’ll “have to wait a little longer” before we hear anything about a potential sequel.[/b]
Source: https://www.pcgamesn.com/destiny-3/release-date