News flash...plenty of small school coaches are already doing this. Like literally the basketball coach (any multisport coach) is also putting in time working with the baseball/track boys/girls (other sport coached) during each sport season...only right now there are restrictions on how many kids he/she can work with at a time so they spend even more time working with several groups.
Schools that push for multi-sport kids will continue to do so, because of their expectations, coaches, community, and culture. Kids already have access to things in some places that others don't. Don't kids within an hour or two of Omaha and Lincoln readily have more access to club activities than others from farther away? Yet schools like Wahoo, Neumann, Malcolm, Milford, Norris (not small), Waverly (not small), Yutan, DC West...all have had success in different sports.
Kids that don't play sports or specialize in one sport today have many reasons. One of the biggest...that we act like is a secret....Sports are hard....and many kids don't like and can't handle hard in today's world.
One thing this may put small towns at a disadvantage of for sure is time and facilities. If a school has 2 gyms....there's only so much time that can be spent on each sport...and often in these communities, the same facilities for school sports are used for youth sports programs. Bigger schools often have more gym space...so are they at an advantage....that's up to you to decide as your own opinion.