This is no April Fools joke: Verizon has updated the Galaxy S6 and S6 Edge software pages with details of the Marshmallow OTAs for the two devices. They currently run Lollipop, so the update will be very welcome to S6 owners on Verizon; Samsung started to roll out Marshmallow for the S6 and S6 Edge in February, so Verizon isn't that far behind. It does come almost a month after Sprint initiated the update for their S6 and S6 Edge, though.
The update brings all the features you'd expect of a Galaxy device with Marshmallow. Now on Tap is there, as are on-demand permissions, which were both introduced as part of the overall 6.0 update from Google. On the Samsung side, users can now search apps in the app drawer and change how the device acts when connected to a computer. For the S6 Edge, there are added functions to the Edge panel, including 'Task edge,' which has the ability to attach frequently used features to the panel, an 'App edge,' which means users can attach apps there too.
While we haven't given it a go yet, there's probably all the normal carrier bloat for *ahem* added benefit as well. If you have an S6 or S6 Edge on Verizon, your device should notify you when the update is available. Check the source links for more information on the respective devices.