I think we should still draw a distinction between what the article author did and what a company like Hashicorp did.

Hashicorp prominently displayed that they were committed to open source and that all of their projects would be open source forever.

They had a CLA, but there are 2 good reasons to do this besides removing the OSS license:

* You may want to be able to also offer the software under an alternate license, which some companies do due to the demands of a corporate client (e.g. one offered with a support agreement)

* You may want the ability to relicense under a different OSS license.

As long as the article author didn't make any promises about continued commitment to OSS, I don't see anything deceptive here (because without such a statement, a CLA usually means you want to relicense in the future)

Hashicorp on the other hand pulled a jerk move by misleading the community as it formed, and which also contributed a lot to both Terraform and the corpus of terraform providers, etc.