James Gunn is ushering in a new era for the DCU, and unlike past era's it looks like he is learning from Marvel in how to plan a universe.
The new DCU is not far away, and it is learning from Marvel in one major way. When James Gunn and Peter Safran took over DC, it wasn't clear how they would go about it, but a full reboot is coming, starting officially with Superman: Legacy - though Blue Beetle's canon status to the new timeline means it predates the first DCU movie. New Batman, Superman, Green Lantern, and Wonder Woman projects are in the works, in various forms, but crucially, the new DCU is not looking to run before it can walk.
  
Whichever way they choose to go, it won't work if the plan
    isn't correct, which the recent past proved painfully. One of the biggest
    problems the DCEU had was bad planning. If James Gunn and Peter Safran want
    the DCU to be successful, they need to make sure the planning is airtight.
    One of the ways he is doing this is by taking a page out of the MCU's
    playbook, as DC plan to announce the first three years of the slate.
 The DCU Is Learning From Past Mistakes 
Even without tangible details of their upcoming movies beyond
    titles and broad stoyies, the DCU is already learning from the mistakes of
    the past. It was originally thought that Gunn and Safran were going to
    announce a full 10-year plan for the future of DC, but the reboot
    announcement included only the first three years. This was a shift from past
    regimes where too many movies would be announced too early, with the
    majority of them not getting released. Early on in the DCEU's lifecycle,
    Justice League part 1 and 2 was announced, but that quickly changed; a Joker
    and Harley Quinn movie was announced never to be seen; and The Flash, which
    was first announced way back in 2014 was only released in June 2023.
  
Having a rough 10-year plan is smart as the first stage of the
    MCU proved, but having the immediate years set in stone first to see what
    works and doesn't work is smarter. This way, films closer to the end of the
    10 years can be changed, but that's fine because they were never concrete or
    announced officially. This is the best way for the DCU to operate as it will
    allow Gunn to tweak the plan based on the reception upon release without the
    studio being labeled reactionary as it has been over the last number of
    years.
 DC Copying MCU Is A Good Thing 
DC has never really had phases the same way the MCU has. With
    the DCU's three-year plan, it looks like DC is copying Marvel, but that's a
    good thing. Marvel's strategy has worked for over 10 years, whereas DC's
    hasn't. Phase 2 of the MCU consists of six movies across three years. This
    is likely similar to what DC will announce, but with a mix of television
    shows in there as well. It makes sense that the DCU would use the same
    planning process as the MCU, especially as it needs this first phase to be a
    success.
  
The new DCU needs to hit the ground running after years of bad
    planning and learning from Marvel is no bad thing. Past eras have tried to
    be too reactionary and rush to things like Justice League because of the
    success of The Avengers. James Gunn's DCU lineup is different from that as
    he is using Marvel's success as a road map for their planning, allowing them
    the space to make changes if needed. The DCU could fail, just like the DCEU
    before it, but if the success of the MCU is anything to go by, then DC may
    just have a hopeful future ahead of it. 
