Hypothetical potential, yes.
Lots of technical challenges for airlines, mainly due to safety concerns... it's form flying.
Also lots of complexity involved in coordinating flight teaming... any one airline is not likely to have two long flights on the same route at the same time, they'd just user a single, larger plane in that case. Lots of avionics and training expense for possibly few opportunities to actually do it in the real world.
I think we're going to need to see lots of technical enhancements to improve fuel burn/carbon emissions, but this one probably isn't going to be one of them... we can probably reduce carbon footprint 90% with SAF and various other efficiency initiatives though.