Mozilla announced that they shut down two products – Firefox Send and Notes.
Both the service was earlier part of the Firefox Test Pilot program, later matured and launched as a product/service.

Firefox Send and Notes
Firefox Send was used to share encrypted files over the internet in an easy drag and drop way. All you needed to drop a file in the browser and get a link that you can share with anyone to receive. No third party involved reading the file. However, unfortunately, people started using it to spread malware and other means which prompted Mozilla to shut down the service couple of days back.
Firefox Notes was a very productive tool used to sync encrypted notes between Firefox mobile app and desktop browser. This service also being shutdown. The Notes for the app already discontinued,. If you have the Firefox notes as browser extension is installed, it will continue to remain installed but no support would be provided and no longer maintained. And you can not install it anymore.
However, if you have notes and want to backup, Firefox provides a way to copy them as an HTML file for a limited period.
While Mozilla already on the news for letting go of employees due to business decisions, it is quite clear that Mozilla now wants to focus on products or services that might generate long term revenue with future growth. Mozilla recently launches VPNs as a paid service with low coat plan options.
It is worth to mention, that a very ambitious test pilot program also shut down last year. The test pilot program brought new ideas as products or services around browsers such as Notes and Send.