Rubroboletus demonensis was described in 2017 to accommodate specimens previously reported as Boletus rhodopurpureus f. polypurpureus (2006), Boletus rubrosanguineus (2007), and Boletus legaliae (2012) as well as new findings (Tibpromma et al. 2017). Consequently, albeit it has been published only recently, in terms of its ecology, it is not a scarcely known species. In North Macedonia, species within this bolete group (R. rubrosanguineus, R. legaliae) sharing similar ecological preferences are rarely found, at no more than five sites in total, R. demonensis inclusive.
Rubroboletus demonensis is an extremely rare species, recorded at only two sites, with one mature individual per site. In view of the fact that it has been reported from oak and beech forest on siliceous soil, also taking into consideration predicted sites, a population size of a maximum of 400 mature individuals is estimated (based on: the probable total number of sites in the country (maximum 20), the estimated number of functional individuals at each locality (estimated to be two) and the template of how many mature individuals each reproducing genotype may give rise to (template used ten)). Habitat reduction is observed and degraded quality of forest stands, however additional data is needed in order to estimate precisely the population trend of the fungus.