Hi Stefan,
I did research all the changes applied to the TMP112AIDBVR and TMP122AIDBVRG4 for the last 4 years period. There is only one PCNs issued but it was cancelled. The proposed change was never implemented on the part.
Why there are 2 revisions? I am not seeing on the PCN system any reason or request for new revisions. The two revisions should be the same. Every change applied to our parts is logged in a "Change Log" system and there is no change log on the system.
In this case you are seeing 1.25C offset, the datasheet spec is at 1.5C. I believe the lot you received is close to the limits. When offloads/BOM changes are being worked on, there are some slight shifts (not a whole lot), we perform characterization to verify that the device performs to PDS spec across the temp range. But differences in material is unavoidable esp with Fab changes.
Hope this help!
Mayrim