Recently, some confusion has been observed in the community about the future of the coverage standards. Opinions float around stating that "There are currently no documented requirements to extend the functionality of the W*S Suite" (fact: in June 2024, WCS extensions have been discussed, and WCPS in Spring 2024 has been adopted into ISO 19123-3 and OGC Abstract Topic 6), "There is a consensus to put all available resources into the further development of the Web APIs" (fact: there is substantial work being invested continuously into maintenance and evolution - see below for details) in an assumed "transition from OGC Web Service Standards to OGC API Standards" (fact: WxS will remain in active use for unlimited time).
Such statements are not correct - rather, coverage work around CIS, WCS, and WCPS is moving forward with multiple activities. In corresponding discussion it has been pointed out manifold that there is a huge implementation basis that needs to be preserved - this affects software producers, service operators, as well as service users. Notably, statements like the above ones are not supported by OGC membership motions or similar.
The following brief summary shows that maintenance and evolution is very active across several standardization bodies:
Bottom line, CIS + WCS + WCPS remain under continuous evolution.
In the case of coverages, OAPI-Coverages and GeoDataCubes constitute additional activities in OGC. They heavily use WCS concepts as a blueprint but assume a different protocol binding.
An important commonality is that all standards (WCS and WCPS), drafts (OAPI-Coverages), and ideas (GeoDataCubes) agree on using the OGC Coverage Implementation Schema (CIS).
On a side note, very often software writers trying out draft specifications have implemented OAPI-Coverages and GeoDataCube implement these as new facades on top of existing coverage service implementations (see, e.g., the coverages part of the OGC Testbed 19 Engineering Report).