Nintendo's Infamous Hotel Mario Has Been Ported to the Sega Dreamcast
(handheldhideout.neocities.org)
Nintendo had probably planned to ditch them for a while, since they could not have reacted that fast otherwise. Chances are they would have announced the Philips thing when they did anyway, or maybe slightly later...
But in every report I've seen, Sony did showcase publicly first, and presumably without Nintendo's agreement, on CES 1991. Nintendo's partnership with Philips was announced literally the day after.
Must have been quite confusing for people attending CES in any case.