Prior to MSFS launch, Charts+ was advertised as coming to MSFS after launch. https://www.navblue.aero/navblue-partners-with-xbox-game-studios-for-microsoft-flight-simulator/
About 8 months ago (Sept 2021) in a Dev Q&A the following question was asked about the progress of Charts+ and a response that it has been “unprioritized for now” was given:
We celebrate 2 years since the launch of MSFS this summer. Has work yet started on Charts+, or is there any timeframe in which we can expect this to arrive in MSFS?