Absolutely key. Absolutely international.
Until noon: no flights
Afternoon:
one flight to Phuket
one flight to Chiang Mai
one flight to Irkutsk (international!)
one flight to Ko Samui
(feel free to add)
Motorway connection ASAP!
It must be a dream to have a full time job at this busy airport (like baggage handler, cleaner).
If this Sino-Thai deal goes as fast as the high speed train, then the airport might be busy until then.