SETEC already sells a $700 CCS1 adapter for the Tesla, and it is available in the US. The SETEC is 200 Amps; I hope the Tesla solution will be more.
One way or another, it is pretty much a done deal that Tesla owners will have CCS1 access.
I expect the Tesla solution for my 2018 model to require a hardware upgrade to allow adapter use*. If it's not much more than $1,000 I'm going to jump at the opportunity because it opens up the less traveled roads in Colorado my wife and I want to use. If the Tesla solution does not work out for us I'll buy the SETEC adapter.
*I'm going by the European experience. Tesla offered older car owners with Type 2 ports an upgrade path to CCS2 use via a hardware upgrade + adapter package. The package started out at 500 Euros in 2019 and now costs 300.
As for CHAdeMO, let me put it this way: If I was offered the adapter for free, I would choose to pay for CCS1 instead. The improved charging speed, and reliability that comes from using an actively supported infrastructure with much more deployment is easily worth the cost of admission.