Finally, it's more than time... It should be both 50mm 1.4 (1993) and 50 2.5 CM (1987). the 1.8 STM is decent for an entry level 50, however, the 1.4 has been put to shame by Sigma (Art), Tamron (45mm), Zeiss (Otus and Loxia) and even Sony (55mm). As canon is putting a lot of emphasis on the lens line-up, the "standard" lens choice has become clearly indecent. However, to compete, they can't just make another Planar. That means bigger, heavier and more expensive...
As for the 50mm macro, that I own myself, it does the job, between f5.6 an f16, but it's kind of the minimum of what one should expect from a modern macro lens. Everything on it is vintage, and it's more than time to release a modern one, with weather sealing, USM and stabilisation.
Personally, I would prefer a 50-60mm f2 with 1:2 macro, than a f2.8 with 1:1 macro, since these lenses are mainly used for medium range close up, reproduction or (in my case) architecture, that is IMO the nature of a 50 "macro nowadays : a zero distortion, flat field, ultra sharp "standard" lens for critical work at medium or small apertures, f2 makes it just even more universal.
So basically, I am expecting the little brother of the 100 L IS, not sure it will happen though.