The French Phototrend site has an interview with Canon:
“The range of full-frame lenses is already well stocked: do you plan to develop (at the same pace) the RF-S range for APS-C hybrids?
Tetsushi Hibi: Regarding APS-C lenses, last year we developed a wide-angle zoom [the
RF-S 10-18 mm f/4.5-6.3 IS STM , Editor's note], and we're really working on strengthening our APS-C line.
But again, it all depends on what the customers want, what they ask for. And we will have to take into account what comes first in this planning.“
And
”With the RF mount open, can you tell us how Canon validates the development of a third-party lens for the mount? Do manufacturers only have to comply with technical specifications, or is it more strategic?
Go Tokura: I want to clarify that as we speak, there are no third-party RF lenses with autofocus available. As you know, we have not adopted an open strategy.
That said, although we have more than 40 lenses available in our catalog, we need diversity in our offering to satisfy customer needs. This means that we are currently communicating a lot more than last year with third-party manufacturers.
All I can say for now is that we have a confidentiality agreement with other manufacturers regarding the type of lenses to be released or their positioning in the market. But I can't say anything more.“
Link to google translated interview.