So the observation here is that this trend of using AI instead of entry level people will, eventually, leave the job market empty of mid-level people, since nobody got the real-world experience that they need to become mid-level people.
Even if true, it still doesn't make sense for any individual business to hire and pay entry level people that they no longer need. If they do this, they are basically running a charity at that point, and likely violating their fiduciary duties. Each individual business needs to cut costs in whatever ways make sense for the health of the business. The problem of not being able to find the people they need isn't actually a problem until later.
So, even if every single business owner in the world reads these warnings and nods in agreement with them, they still have no incentive to hire entry level people. That would just increase their costs while allowing their competitors to keep their costs low. It wouldn't be rational for them to hire these people they don't need.
The most likely way this plays out (assuming it is actually true) is: when the day comes that mid-level people are needed but none are available, entry-level people will be hired instead, right into mid-level roles. Also, senior level people will be retained longer, paid more, possibly even invited out of retirement, to train and coach these entry-level people who are needed in mid-level roles.
There you go, problem solved. It might be a bit pricey when the day comes, quality and reliability might take a hit, but those costs will be felt industry-wide so all companies will at least be on equal footing.
At no point will warnings about a talent drought prevent any employers from using AI instead of humans as much as they possibly can.