I probably shouldn't be trying to sum up canon's entire marketing philosophy in a post. But I am thinking that instead of gravitating toward EF-S lenses, they are gravitating toward EF-S lenses when a "market" for that lens is created by either a price advantage over an EF lens, or when the 1.6x crop factor comes into play (like needing general purpose zooms that start at 15 mm or 17 mm). For example, the EFS 55-250 IS sells for about $225 while the EF 70-300 IS sells for ~$600. Price advantage thus we get an EFS lens. EF 70-300 non-IS sells for ~$200, no true price advantage, so no EFS lens.
I bring this up as I've seen people express concern that if a new non-L prime was ever released that it would be EFS. My guess is that it would be EF as they could sell that to both FF and crop sensor users. I see Canon no longer producing a non-L EF prime only if they determine there is little market for one. But some 5D owners use the 35 f2, 50 1.4, 85 1.8, etc. So I don't think those replacements, if they ever come, will be EFS.
So, in short, I only see EF-S lenses being released when a market is created either due to a technical characteristic of the crop sensors or a price advantage. So this may be a limited trend toward EF-S, not a complete trend. Not that Canon is consulting me or anything.