I’ll take it one step further.
I think 5e will be the last edition period, with it migrating to primarily a digital product line that will evolve over time. So instead of an official 6e, it will just be D&D, but with updates and changes that will keep it fresh and relevant.
When there is enough drift to the PHB to warrant it, they will likely issue an updated version, but it will be comparable with all old material.
It took 45 years and 5 editions, but they finally have a version the continues to see double digit sales growth 5 years after release. Sort of like baseball or football, which went through a long period of constant change before finally finding a sweet spot and settling into forms that change much more slowly now.