Sources:
https://medium.com/predict/the-worlds-fastest-blockchain-exceeds-1-million-transactions-per-second-8931df09320d
https://tectum.io/
They don't have supporting documents for this claim. The medium link you provide is an interview to the team member and all word that he said is just his opinion. Even the 1M TPS has no basis at all, The video on the medium is just a graphical representation of how nodes work. They don't have any testnet data available and also they will surely be on major publishing website like coindesk and coinstelegraph.com if they really have what they are claiming. The only source for there claims is just there own written medium blog.
1M TPS is insane. LOL
Exactly
The question is...who has high TPS with decentralized consensus scaled?
There is only one. Avalanche
Vitalik himself has tweeted about it