You're wrong in looking at orcas and oaks. They are too far apart the evolutionary path so that it is meaningless to think of them as competitors.
Darwinian selection is the species versus the environment and this environment can include other species, as well as other individuals in the same species with slightly different traits, that will compete for similar resources as well as the climate.
It's very difficult to even think of who is actually a competitor of who, was Facebook a competitor to myspace? Youtube to myspace? Tumblr? Livejournal? These were all platforms competing for creators and attentions so I think they are all in a certain degree of competition.
I think a sale in this space is the gathering of attention (i.e. time and/or money). But thinking of what's required to actually learn might offer some insight on why it is hard to compete in this space. To learn people need to spend effort and although it can be made fun it is extremely difficult to be made effortless. On the other hand, entertainment is effortless but it offers little learning. So these are two parameters that need to be tuned. But I think the problem here is that the algorithm benefits entertainment much more than it does learning, entertainment is more valuable for youtube's ultimate purpose (to grab the viewers attention) and so to thrive on youtube people that want to offer learning have an uphill battle to fight.
So I think this move is Youtube acknowledging that learning is also desirable in society and can be pulled apart from the loop and monetise in its own way. In other words, it's an evolutionary split, cells all have a common ancestor but some cells evolved to harvest the sun energy while others evolved to harvest the energy of other cells. Learning being desirable has given rise to platforms such as coursera which are also multi-million businesses and Youtube probably sees them uploading most of their content to youtube anyway (usually as private videos), so why not adapt the platform a little bit to give existing creators a chance to stay on youtube instead of moving to other services?
This move won't really solve the problem of entertainment predating on people's time over learning (if we consider that a problem) but it's not really intending to do that. So I believe if we want to look at things from a darwinian perspective we have different angles to look at. Creators that produce entertainment content will probably still benefit more than the ones that produce hard to approach but very good learning material, why? because attention is the most valuable resource out there. This move offers little solution to that, but, on the other hand creators will have more tools inside the platform to manage learning which will completely change the current online learning business and we'll see platforms like edx and coursera in need of offering more value to pull themselves apart from youtube. Because users from these platforms (including youtube education) are already searching for valuable learning experiences we might see evolutionary jumps in this particular area. Though this might also be a race to the bottom where youtube captures the segment and then changes to optimise attention-seeking. We'll see.