I highly recommend subscribing to the API announcements here on the forums, as this is the place where you get exactly this kind of information.
Thanks, will do 
This is good news for me! First had the fear it could be the other way around, so that I would have to configure the longer chain consciously from June 2021. But so I can wait easy until the change takes place and can, if necessary, still react until 01.09.2021 (then when the Intermedia expires).
Assuming I have understood everything correctly, my questions are thus answered.