Yes and no. AT would be it's primary role but direct fire support would be a very close second with a second vehicle type replacing the towed / pack infantry support guns / howitzers. The idea is to replace, not just the towed AT gun / recoilless rifle but also its tractor as well as the traditional infantry support guns / howitzers, with something far more mobile and survivable.
There would be an AT platoon with three or four sections, one for each infantry company, each with two vehicles also the infantry would retain their Bazookas, PIATs, etc. this would replace the towed guns only. The same would apply to, not only, the STUG, but also heavy mortars, AA, reconnaissance, pioneers and potentially APCs. Sort of an organic Armoured Support Company (ASC?)😊 that can split into sections to support individual companies or concentrated at battalion level as a reserve. Basically it would turn each light infantry battalion into a combined arms battle group while not detracting from their core infantry skillset.
What I am doing is implementing a version of plan Beersheba 60 years earlier at battalion rather than brigade level. On the flip side there will also be infantrymen / riflemen / assault troopers imbedded organically in all armoured / cavalry units down to troop level, with similar AT, STUG, mortar, pioneer, etc elements at regimental level.
Post WWII three infantry battalions where renamed go become the first three battalions of the Royal Australian Regiment, effectively an infantry brigade, the core of Australia's first standing army. At this time it was also intended to form a regular armoured brigade, supported by two similar reserve or CMF brigades. The armoured brigade never happened and the infantry brigade eventually became an infantry division with other elements, including armour in support, but an infantry brigade with organic supporting armour and an armoured brigade with organic supporting infantry, each backed up by a pair of reserve brigades of similar establishment would have been quite achievable and affordable.