LibreOffice comes with its own support these days... RPMs are provided out of the box too. So it makes sense.
Who can you call if you have a technical issue with LibreOffice? One possible answer used to be Red Hat if you had the entreprise version and a support contract.
Red Hat knows if their customers are buying Red Hat license to get support for LibreOffice. I would assume this is a case only for very small number of customers, as Red Hat is mostly focusing on server product. And today companies can buy the same support from LibreOffice directly, so there is no point for Red Hat to compete against LibreOffice here. It's win win.
Even then it would be vastly different than working with Red Hat/IBM. Most procurement offices probably wouldn’t be fine dealing with such a small partner.
The fact is with Oracle and Red Hat having withdrawn, no serious company nowadays supports OpenOffice/LibreOffice. This part of the market which was already mostly dead when serious online solutions arrived is now pretty much officially buried.