The last 50 f1.4 was sold 30 years ago; then the 50 f1.2 was presented in 2007, and since then, no more 50 f1.4 was ever seen with the Canon brand. I don't see why they would want to present an RF 50 f1.4 lens in the 1000/1500$€£ range (40/50% less then the 50 1.2), 90% of people would then not spend 1000$€£ extra for just a third of a stop more brightness.
And they did the 85 f1.4 in 2017 because both 85 f1.2's suck and have terrible AF, no one was buying them anymore, and Sigma Art lenses were beating the sh*t out of them (and they even failed, as the 85 Art is sharper then the Canon at any aperture); and they even did it too late, as the last DSLR was presented in the 2020, just three years later, so they presented the 85 f1.4 for a system that was already on the death bed, as Canon original R came out in 2018, just a year later then the 85 f1.4 L (of course the lens was in the pipeline since many years before presentation, you just don't stop it, then).
Consider that, apart from the 1Dx III, from 2017 to 2020 the only DSLR's presented were the 6DII (terrible camera), the 90D (good camera, but wouldn't call it a milestone), all the other cameras were cheap Rebels.
EF system was dead already when the 85 f1.4 L came to the market; lucky for us they gave us adapters, and EF lenses work as good as RF lenses, so the legacy still lives on. But we'll see if Canon will ever manufacture a RF 85 f1.4 and I'm pretty sure they won't, for the same reasons of the 50's.