Yes, hiding romantic interest has the potential to deceive someone who isn't savvy about the game-theoretic incentives on you to avoid showing it. Directing lying to someone who asks by saying that you don't have romantic interest that you actually do have would definitely be deceptive (but even then, there might be a justification if you feel that the DTR is the wrong place to reveal your romantic interest).

And in such cases directly lying tends to be a dominated strategy. A simple "I don't do Defining The Relationships on a second date." shows stronger personal boundaries, self awareness and a sense for the appropriate time for self disclosure.

An exception (a game where non-disclosure does not dominate explicitly lying about relationship preference) is possibly with particularly high status and gender typical women who operate at a level where verbal symbols used for purposes that are more or less divorced from application to mundane reality. In that case a "I'm not interested in a relationship" or "we're not going to have sex" can prompt an instinctive contrariness and an inclination to challenge your declaration.

Interpreting that level of signalling as 'deception' would be as absurd as interpreting a metaphor literally and dismissing a poem as a lie. It just isn't supposed to be a correct factual description.