New groupset: Shimano Cues. Replaces Tiagra, Sora, Claris, Deore, Alivio, Acera and Altus.

https://bike.shimano.com/en-US/information/news/shimano-unveils-new--highly-compatible-ecosystem-with-shimano-cu.html

"Shimano unveils new cross-compatible CUES groupsets for city, touring and mountain bikes, consolidating Claris, Sora and Tiagra"
https://road.cc/content/tech-news/shimano-unveils-new-cues-groupset-family-299609

CUES consists of three levels of components across all riding disciplines: U4000, U6000 and U8000. The U4000 range is 9-speed, U6000 is available in both 10- and 11-speed and the U8000 comes with 11-speed components. All of these are cross-compatible, to a certain extent.

You will find all of the CUES groupsets designed to use an 11-speed chain - meaning all of the cassettes have the same spacing between the sprockets and can be run with any existing 11-speed chain

CUES components will not be backwards-compatible with outgoing Tiagra, Sora and so on because the pull ratios are different to the older groupsets.

Seems like a sensible development.