I dont think we would have seen the ME262 much before the end of 1943. Even then it had some major drawbacks. The biggest one being its engines.
They could only last a maximum of 12 hours before change, where as the UK Meteor was perhaps the better fighter with much more adapted and usefull engines. This no doubt would have been rushed into production along with US jets if the event had happened, so at best, as in WW1 any new technological improvement by one side is always countered by the other.
A good ME262 history can be found here:
The Messerschmitt Me262
I do like discussons where opposing points are listened too and agree very much on this as a way forward.