If all you are doing in Europe/ME is SYD-LHR-TEL-LHR-JFK then that's fine. What you can't do is add any more "long Europe from the UK" segments.
I'm not sure why anyone would voluntarily go through the UK at the moment though... I'd consider going SYD-FRA-MAD-TLV-MAD-FRA-DFWorORD-JFK which gets you on AA across the pond.
Remember also that you're allowed 6 segments, albeit only 2 stopovers, within North America (and you can now go back through the origin) so make sure you use them for the miles!