I guess it might depend on what you mean by plans, as in, they have a working plan or are they just intending it to be used for that, but NASA clearly feels it is the rocket they would use for going to Mars:

https://www.nasa.gov/centers/marsha...-is-the-rocket-for-the-ride-to-mars.html

NASA’s Space Launch System is the Rocket for the Ride to Mars

The SLS will be NASA’s first exploration-class vehicle since the Saturn V took American astronauts to the moon more than 40 years ago. It will expand our reach in the solar system, launching crews aboard the new Orion spacecraft to explore multiple, deep-space destinations. A fleet of robotic spacecraft and rovers are already on and around Mars, but to fly to and land humans safely on Mars requires a next-generation spacecraft – Orion. SLS will ensure it gets there.

If the program survives how ever many Whitehouse administrations and Congressional sessions necessary to get an operational SLS / Orion to Mars... I suspect SpaceX will have people waiting on Mars ready to greet the Orion's arrival.

Bingo.

Any use of SLS to go to Mars, by NASA PAO or anyone else, is purely speculative and conjectural. There are no plans for such usage.

In fact, there are no plans for any SLS beyond: one unmanned test, one lunar flyby test with crew and one crewed lunar landing. SLS was intended to launch a large probe to Jupiter in 2025 but that is much in doubt now.

I'm curious to hear your expert punditry on what NASA's real "agenda" is then...

NASA's "agenda" for SLS is as already stated: 3 planned flights. The fourth SLS launch was recently, after being in doubt for some time, rescheduled for a different launcher: https://www.extremetech.com/extreme...-launch-europa-clipper-commercial-rocket

And one doesn't have to be an expert, one only needs the ability to read.