My impression is that delta increase of registered users is growing every day e.g we might have entered some accelerated growth phase.
Is there any data available to make a graph, or even an existing dashboard with such a graph?
You can play with
Btw I can confirm your impression that on the last week the rate of new users is on a raising curve.
Here is a graph of new DevOps users per day. It's very stable, with a natural weekly cycle. The first peak is the first day of private beta. I don't know the cause of the second peak in early April; could be a Reddit post about something on the site, etc.
Source: SEDE query
I've been regularly checking the Users page (new users, creation date tabs) - shows all users that signed up in the past 46 days. There are peaks now and then - mostly at the beginning of the work week, but the average remained fairly constant in the past few months.