As has been said in this thread before, I dont want to speak FOR ryan and mess up his thoughts and ideas, but as far as the straightforward questions Im happy to tell you.
Yes, in the advanced and team classes and as well as open mats takedowns are trained a lot. There is also a wrestling class and the wrestling coach trains at all the jiu jitsu classes, and is always happy to answer questions or work one on one on something. Ryan and Seph encourage this as much as possible.
The takedowns are mainly trained in the wrestling classes and ground stuff is mostly trained in the jiu jitsu classes, however we are shown a variety of trouble shooting/finishes for takedowns and sweeps as they are related to the task at hand in the jiu jitsu classes. As you can imagine, some sweeps end very similar to takedowns so sometimes they can overlap.
Generally people start from the knees as an issue of space and safety however people working specific stuff do stand, and especially more so as people start leaving or in the less crowded advanced classes. It is certainly encouraged. I will tell you in my personal experience rolling with Ryan, if I am not (attempting to) control Ryan when I stand up to pass, he stands right up with me and starts wrestling.
What he advocates is very dependant on the situation and the minute details of said situation, so your question about conceding the takedown could have 100 answers. We've learned ways to shut people down doing that, and we've drilled sitting through to guard both. The manliest option is always encouraged and emphasized.
Your post seems to be asking the question do Ryan and Seph encourage stand up and learning the top, and the answer is very much so. When I came to the gym my top game was non existant. I started from my back and finished from my back, win or lose. Theyve completely changed how I roll, for the better and really gotten me to open up and learn and get away from the mindset that I am a superfeather, so I have to play guard. I feel much more manly since joining the team.