"We had originally planned for the Elite Dangerous major update to release in December 2020, but, in the context of the current Covid-19 environment, we have now set a Q1 2021 release date"
Lets forget about the planned 2017 update which then got moved to 2019 to then be moved to 2020 and now 2021.
Thats not a plan...
Sure it is, just one that ED players suffer for. The plan is to use the core talent at Fdev to work on newer games that will generate more revenue. Once those are out and past their initial sell phase, move them back to ED.
ED is an established IP but is a niche game. There are few who want to play it who don't already have it so Fdev as a company has a pretty clear picture of their financial projections (setting aside covid). The "Delays" were one of two things, likely both. 1. internal shifts of what they want to achieve with the next installment. 2. Shifting of talent around to accomplish goals that will better suit the company.
It very much is a plan, just not one you particularly like because you likely don't care about either the other game or Fdev's profitability.
Edit- I also imagine they have been working on converting/prepping to be able to release it on Next Gen consoles and I'm pretty sure New era will be the "base game" for next gen - if there will be a "free upgrade" to current ED to next gen for PS4/Xbox players - I have no idea. I'm sure it's been discussed but it's likely an ROI assesment.