The pair had held several discussions in recent months with Kidwell detailing to Taumalolo and other senior players his plans to revamp the Kiwis playing style - which was largely centered around the devastating North Queensland forward.
"I haven't had a conversation with Jason face to face or on the phone, that's the most disappointing thing," said Kidwell.
"I respect his decision but a conversation between myself and him would have been a good thing to do.
"We've made a number of phone calls, emails and texts so you'll have to have a conversation with JT (about his reasons)."
Fellow selector Tawera Nikau confirmed he had spoken to the 24-year-old in the moments after the Cowboys grand final defeat to Melbourne, and received no indication of his plans to jump ship.
"I spoke to Jason after the grand final on Sunday and congratulated him on his effort," said Nikau.
"We didn't really talk too much about the Kiwis but, as far as we understood up until the other day, we thought he was going to be part of the Kiwis."
Reports on Wednesday suggested Taumalolo's decision was made in protest over Kidwell's hardline stance in banning former test captain Jesse Bromwich and back-rower Kevin Proctor from the World Cup for disciplinary reasons after they were embroiled in a cocaine scandal following the Anzac test in Canberra.
Despite Taumalolo's apparent disapproval over the severity of their punishment, Kidwell said he'd never raised the issue with team management.
"We definitely haven't had a conversation about that," said Kidwell.
"Everyone's going to have their own opinion but at the end of the day we've made that strong decision for the jersey.
"We're trying to build a new Kiwi spirit here and we're not going to condone that behaviour and we're moving on to the players that do want to have a strong culture."
Kiwis captain Adam Blair was not in attendance but said via telephone link he was disappointed by Taumalolo's shock switch of allegiance.
"It's disappointing for me but he's in his own right to do what he wants," said Blair.
"We've got to put our energy back into the group that we have.
"I'm going to lead that from the front and (show) how much that jersey means to myself and my family and the people that have worn it before me."
It remains to be seen whether Taumalolo has any intention on making a return for the Kiwis in the future, while Nikau denied his days in black and white were over in the eyes of selectors.
"We've never shut the door on any other players in the past," said Nikau. "Obviously it's going to be assessed after the World Cup."
Along with Taumalolo, fellow Kiwis eligible players David Fusitu'a, Manu Ma'u and Sio Siua Taukeiaho have also elected to play for Tonga, despite having been part of New Zealand's wider training squad over the last month.
Unlike Taumalolo, Kidwell said the trio informed him of their intentions last week - although Tonga coach Kristian Woolf indicated he only learned of their availability on Thursday morning.
When asked if he was still enjoying his role, Kidwell replied: "If it was easy everybody would be doing it."
