I meant a publicly-accessible roadmap. Canon doesn't work that way, apparently - they obviously have internal plans.
But I honestly don't understand your position. They aren't going to abandon EF! Even if they never make another EF lens, which I'd be very surprised by, they will continue to support existing ones for many years. Beyond that the bottom line is: there are no guarantees. When you buy stuff, you don't know what will happen - but Canon are the biggest player in this market so they are unlikely to go bust and leave you with gear that can't be serviced, and the resale values hold up well, so I don't see why it's such a big deal. I still say the situation is essentially the same now as it was a year ago - all lenses have deficiencies. Some will be replaced, some may never be, we don't know which. You have to buy what suits you best at the time. You'll probably want a new body at some point, if you go with an R-series, they'll take your existing glass. If the new lenses you want are RF then you'll have to buy an R-series if you want to use them (this is the only difference). But by then there will be a choice of bodies and one will likely meet most of your needs (but no body is perfect, regardless of mount or manufacturer). *Shrug*
Service is one thing, bringing out new and improved lenses or bodies another. For over two decades the path was clear and one could happliy buy into the system, assured that there is one system. That was kind of a guarantee, which made this a very safe home. As I said, in my opinion some EF-lenses need improvement, which won't likely happen anymore. Therefore you are forced to buy into the new system, if you want to get these improvements. The resale values of older lenses will drop, if better alternatives exist in native glass. Since I am not made of money, this is naturally of some concern to me.
Another choice I am confronted now is to stay with canon (not likely with the EOS R), or switch to another system all together, since buying another body is a given fact someday. Canon may bring something to the table, but judging from the latest releases, I am not convinced that they will or are able to. EOS R is not for me, too many things that annoyed me (ergonomics, not working features) during my tests with it. If they would have done it differently, I would not question this at all.