Hi @jingpan ,
I'd like to add comments for considering (using SDK_2.x_LPC5526 by way of example).
1. Document Title
Are you referring to the document titled "MCUXpresso SDK Release Notes for LPCXpresso55S28", i.e.,

I think not as this document does not contain drivers and middleware version numbers.
Rather, you are referring to the document that has a very similar title "MCUXpresso SDK Release Notes supporting LPCXpresso55S28", i.e.,

The titles are confusing and ambiguous. Who decides these document titles? 🥴 It's not even matching the PDF's file name.
It may be nitpicking but in my opinion, the latter document should bear the simple title "MCUXpresso SDK Changelog" instead. That's much clearer and matches the name as shown in the MCUXpresso IDE menu.
2. Identify Changed Versions
This is how the "Change Logs" document looks like:

Why don't you mark changed driver version, e.g., by emphasis (bold text) or just note the SDK-Version after the version number?
3. Missing FreeRTOS Changelog
Why is the changelog for FreeRTOS not included in this document? Instead it is kept in a separate text file that resides outside the doc path:
SDK_2_11_0_LPC5526\rtos\freertos\freertos_kernel\ChangeLogKSDK.txt
4. Download SDK Documentation Separately
Using MCUXpresso SDK Builder I cannot download SDK documentation separately any more for SDK V2.11, see screenshot:

Why is this?
Thanks.
Daniel