Yes, this user is uncessarily spamming. He has spammed the same thing on reddit also https://www.reddit.com/r/Bitcoin/comments/bsfffv/btc_wallet_error/
The facts are clear
Blockonomics only asks for your xpub https://www.youtube.com/watch?v=Kck3a-9nh6E to accept BTC. In fact we have a direct to wallet philosophy https://www.blockonomics.co/merchants where we never ask for private keys
How could get it ever get acccess your coinbase account ?