I think people want to project time travel onto Gary Seven because they perceive Doctor Who
parallels, and because the ST episode used time travel as a plot device to enable the crossover. But if A:E had gone to series, it would've been a present-day, Earthbound show in the vein of something like The Man from U.N.C.L.E.
-- a pair of operatives with a secret HQ and high-tech gadgets which they use to tackle threats to world peace. In fact, the series pitch document called it "Have Gun -- Will Travel 1968
," a reference to the Western that Roddenberry had been story editor for years earlier, a series about a highly intelligent, refined, capable "champion for hire" who travelled around solving people's problems. The pitch also heavily stressed that the show's setting and focus would be contemporary, that it would deal with very human crises and antagonists. There isn't a single mention of time travel anywhere in the pitch document, except in mentioning that the Trek episodes where they travelled back to the 20th century were among the show's most popular -- but that was to support the point that A:E would be interesting because of its present-day, real-world setting.