Is Microsoft Access being phased?

I think theDBGuy is probably correct. That falls under the category of people misinterpreting what they see or read.

It was from someone who works with a commonwealth government agency, as they have been told that's what's happening and they are building something else to use.

It's highly likely that they were simply referring to themselves rather than Microsoft. For example, in one place of work that I know of, they are starting to phase out Microsoft Access from their ecosystem because of tightening security requirements. No macros of any kind can be executed unless it's digitally signed with a verified digital certificate. And because the company didn't want to invest in a digital certificate framework, people are starting to find another way of doing their jobs without using Access.

It was from someone who works with a commonwealth government agency, as they have been told that's what's happening and they are building something else to use.

So ask them where they heard it!

The reality is that Access has always been denigrated by IT departments. This is generally due to IT departments wanting control over their data but Access shifts some of that control to end users. There is some sense in their feelings, but there are workarounds.

But there is no truth to this rumor, and its likely this person is being fed a line.