Vettel was pictured talking to Horner and Helmut Marko last weekend in the paddock, and appeared alongside both men on the Red Bull-owned Servus TV during the week.
The German denied that it had anything to with prospective talks that now appear will not even take place.
He also discussed Racing Point‘s emergence as a big force in the midfield, appearing to be in contention for best of the rest with Ferrari and McLaren.
“I think Racing Point left a very strong impression, and certainly are in a good place for this year,” Vettel said.
“I know part of the team, I know some members of the team quite well from my past and for a long time, so I think it’s obviously a good opportunity for them this year to have a good car to fight with and try and improve from there.”
Vettel was confirmed as being replaced at Ferrari for 2021 by Carlos Sainz, with the team never holding fresh contract discussions with the 33-year-old.
He also said that informal talks had taken place with Renault before the announcement that Fernando Alonso would rejoin the Enstone team alongside Esteban Ocon.