If it's not out within the next 4 years, it will officially be the case that more time has passed between Elder Scrolls 5 and 6 than Elder Scrolls 1 through 5.
17 years between Arena and Skyrim compared to 13 years so far since Skyrim's release in 2011 (and counting, almost up to 14 years if counting from calendar year alone).
When Skyrim came out, Bethesda promised free new Bethesda games for life to parents of kids born on 11/11/11 who named their child Dovahkiin. Young Dovahkiin is almost in high school now, and of the promised free games, their parents have earned a whopping:
That announcement and the "development progress" follow up was fake to placate people getting angry over Failout 76. If they even started to working on it, it was 2023 the soonest.