checked the original language in German, the commitment sounds pretty weak:
- it says "for the time being" & "it is not definite that they won't resume development work in the future"
- main R&D focus is on "electrification, electric drivetrains and battery development" -> "electrification" can also mean hybrids
- there are "currently no plans for new engine developments" -> this sounds like he is referring to from-scratch developments, and this obviously does not exclude upgrades and minor improvements
since an engine platform is usually good for ~10 years and they just completed the latest iteration, it's a statement they can easily make at the moment.