Hi [NAME],   I understood your point and I would too want to know what is the reason it is pulled from the updates, but I can't find any public release statement about it. I'm unsure if the server is in contract, but what's worth, probably try reaching out to call support to raise a ticket to engineering to check if there is any release statement or note about the version release on 2.14. To my opinion, if OME prompted to downgrade and 2.14 version has been removed from download site, it would be recommended to downgrade, to avoid any issue caused in 2.14 which engineering decided to pull it out. 
I saw this back in 2020 sometimes for drivers or other firmware.. and see posts from last year. I tried searching to identify if there was some legit reason to downgrade.  I could not find any.  It would be helpful of such a document was found in the info link in OME for that item.. assuming there is a legit reason to downgrade. I don't fetch new firmware/BIOS/drivers from the web, I let OME do its job and fetch from the catalog.. so the idea that I somehow overupgraded beyond the catalog is absurd. Seems whomever is tasked to maintain the catalog at Dell needs to review what's going on.  Otherwise, if there is valid reason to downgrade, I'd love to have more information than the Downgrade status in my OME for a number of servers. I'd provide the specifics as to the version I have versus the downgrade, but I recall it was just the minor step down and on the 730 series.. because I'm upgrading the console with fleeting hope that somehow it will correct the catalog.. Keeping the catalog up to date is a rather critical component to patch orchestration.  While I find my own maintenance windows to do these upgrades (and.. maybe downgrades..), others likely automate the process.
R730/XD BIOS Downgrade