Tango ... I don't believe mandating a fixed separation of the elbows up to a certain point in the swing to be the best way to teach what I perceive you wish to teach. Instead teaching proper use of the forearms will encompass this area of the swing. It is the "short hands" segment (see prior videos) that results in building structure in the forearms ... and this is what leads to the equidistant separation of the elbows.
To answer your question ... on the surface one could talk themselves into teaching a fixed separation of the elbows up to contact ... however, those that do so are inadvertently grooving an Inside/DTM pitch. You won't see that relationship on outside pitches. On outside pitches the lead-arm will lengthen .... which brings up why there are better approaches ... including Yeager's lead-arm work. Don't believe me ... hit some balls low-and-away ... then pause your swing at impact and review the elbow distance relative to what it was earlier in your swing.
TY. I agree it doesn't have to be taught unless the hitter is confused with keeping the elbows apart. The short hands video looks like the elbows will snap closer together at or slightly after contact.