Fwiw none of that is specific to segwit, all prior bitcoin upgrades in the past were structurally similar. Back in 2012 P2SH, for example, effectively replaced

Fwiw none of that is specific to segwit, all prior bitcoin upgrades in the past were structurally similar. Back in 2012 P2SH, for example, effectively replaced the whole script system (with a copy of itself nested inside a hash).