European Space Agency today announced that it is ending the mission for Sentinel-1B satellite.
They plan to launch Sentinel-1C in the second quarter of 2023, a process typically followed by 3-6 moths of the calibration process. Until then, there are only data from Sentinel-1A available, meaning that the cadence is longer and that some areas are not covered at all.
Official announcement:
and
The impact to the observation scenario is best described in this tweet.