quoted

[Hemant] I got following recommendation from the Linux Foundation legal:
"For files that are e.g. release scripts and documentation, these are
typically understood to consist of contributions that are copyrighted
by their contributors. So even if there isn't a notice in the file, it
would still generally be understood to be subject to its contributors'
copyrights and to be licensed out under an open source license.

As you suggested, adding copyright and license notices can help
clarify these specifics for downstream uses. We have recommended as
best practices that projects add something like "Copyright The
_________ Project" or "Copyright The __________ contributors". I think
your suggestion of "Copyright The DPDK Community" is fine. And yes,
I'd recommend including the appropriate license notice and/or SPDX
identifier in these files as well.
Just to be clear, also, we _don't_ recommend removing pre-existing
copyright notices unless you are the copyright holder in question.
It's generally understood that it's fine to add general copyright
notices where accurate, but only the copyright holder should remove or
modify their own notices. "

[Hemant] So, "The DPDK Project" or "The DPDK contributors" or "The
DPDK community" - anything is fine, we have to use just one of these
consistently.

After some discussion intel would prefer to keep the license as is on the release notes. 
Other contributors/companies can add respective SPDX license for their contributions

Marko K.