Stick with it for five (5) years consistently, then report on it.
They're the ones that probably have access to the most accurate statistics on Linux market share, and they're not liking what they're seeing.
The success stories are there but the failures seem to get more press. Which isn't all that surprising IMO.
It's also worth noting that the Dutch tax office this article is about has until now been running on an in house office solution, they had only recently decided to move to Microsoft 365 but for geopolitical reasons this is no longer a good option. The rollout had only just started.
They do run windows but that is not planned to change anyway, this is about their office suite.
For example, When Munich in 2013 migrated to Linux:
"In 2016, Microsoft relocated its German headquarters to Munich. "
"In 2018, journalistic group Investigate Europe released a video documentary via German public television network ARD that claimed that the majority of city workers were satisfied with the operating system, with council members insinuating that the reversal was a personally motivated decision by mayor Dieter Reiter. Reiter denied that he had initiated the reversal in gratitude for Microsoft moving its German headquarters from Unterschleißheim back to Munich."
It's not just that they don't want to lose a customer - they don't want lots of examples out there of how it can be done.
There would be very little to talk about.
The harsh reality is that projects like ffmpeg and SQLite are wild exceptions to the rule. You need more than a handful of well engineered OSS components to run a complicated business like this.