Yeah, but if you read their RF 'white paper', it makes me hope they'd be able to push the giant front element back and enlarge the inner-most—more like the old symmetrical design lenses for 4x5. Like a Rodenstock 90mm...
Fun that you mention Rodenstock, The 90mm f4.5 is my favorite WA on my Technikardan. However don't forget that 90mm on a 4x5 is roughly equivalent to a 25-26mm. The equivalent for a 17mm would be the Rodenstock 55mm or Schneider 58mm; both lenses are smaller but their image circle doesn't allow any practical shift possibilities. The only very wide that allows a good amount of shift is the 72mm XL Schneider (+/- 21mm equivalent) at the cost of a 95mm thread and is unusable without a center filter. So I am not sure if a 17mm TS-E can be done without a bulbous lens. RF mount could allow better corrections though.
As a heavy user of TS-E lenses, I don't see Canon replacing them soon; the recent 50, 90 and 135 are IMHO here to stay (it took them 26 years to replace the 45 and 90). Even the 24mm is still top notch (despite it's sometimes bad looking blue/yellow fringing), the only one that could be improved is the 17 TS-E since it flares like hell in almost any situation. The addition I would like to see is an EF 35mm f2.8 TS-E, since Canon has the most comprehensive TS line, but 24 to 50 is quite a gap.
As TS-E work is a slow process and includes most of the time the use of a tripod, an adapter is not really a problem, but making an RF only TS-E replacement would be a major problem for a lot of pro users (including myself) who work with DSLRs (basically the majority of pros in sport/architecture/fashion/studio/commercial photography).
Canon know very well what THEIR users want, we'll see a double line of L USM lenses (24 f1.4, 35 f1.4, 85 f1.2 135 f1.8-f2 IS (and maybe a 100 f1.4 to compete with Nikon/Sigma)) and a "consumer/video" range of STM IS lenses (24 f2-ish IS, 28mm f2-ish, 85 f1.8 IS). Add a few f2.8 and f4 WA and standard zooms and a couple of macro lenses and you are set. The big whites will stay EF for the next 5-7 years (the fly by wire implementation on the V3 400 and 600 is a sign in that direction).
Not to forget the EF to RF transition will be much less brutal than the FD to EF since the adapters will work seamlessly for all EF lenses, so there is less of an absolute need to rush every lens now. Nikon is in a different position since their lenses though adaptable, will have a different level of features depending on their generation.
Look at what Sony did; in abandoning the A mount, they made their A mount users mad. They had to make that choice since A to E is not at all seamless, contrary to to EF to RF. Canon is not in the same position, since every single EF lens made since 1987 will works on RF cameras like a native one, at the slight penalty of an adapter. But the adapters are actually adding features to EF lenses, contrary to Sony A to E or Metabones EF to Sony E adaptors that just cripple your system.
IMO what is more important is to release another camera relatively soon with a more "pro" feeling in the 3500$ range, to show what they really can do with FF MILCs.