It's perfectly appropriate for our current cultural authorities (I note the museum consulted Stonewall) to bring our thinking in line with the most overtly patriarchal, penis-worshipping force to have ruled the Western world. Ancient Rome considered adolescent boys fair sexual game but, on reaching full personhood - only available to men - they had to stop 'receiving' penis, or be deemed a woman and therefore not a real person.
As Dr Malik says in the article, calling an Emperor a 'bottom' was a massive insult intended to demean & undermine his status. To the Romans, a 'bottom' was as lowly as a woman; definitely unworthy of his laurels. This only supports the theory that transphobia was rife in the Roman Empire, too. Whether Elagabalus was a gay man or not, it's our responsibility as the New Improved Patriarchy to honour this aspect of his legacy and call him, as the Romans did, a woman.
The poor sod's probably rolling his eyes in the Fields of Elysium, muttering (in Latin) that he should've known those dumb Britons would eventually drag this one out of the mud.