DfT» and
TfL» have just agreed a new expansion of contactless (formally a contract placed by DfT). It won't go further than now on the
GWR▸ lines, but will involve all stations. It will eventually lead to using railcards with contactless, or at least some of them. There is no proposal to extend
Oyster▸ coverage, for technical reasons.
This article from IanVisits provides the details, such as they are known now. It's based on the 2019 consultation, and the final choice of what exactly to do and where to draw lines on the map has not been announced.