Like the Dodgers aren't the true Dodgers; the (baseball) Giants aren't the true Giants; Rams aren't the true Rams; the Colts aren't the true Colts; the Jazz aren't the true Jazz; the (football) Cardinals aren't the true Cardinals; the A's aren't the true A's; the Braves aren't the true Braves...
...for starters.
There is a difference, what makes the Vikings the Vikings was when they played outdoors in the winter.
Basketball and Baseball are different weather type teams. Football is unique in that aspect, especially when they play up North like Minnesota, GB, Pitt, Chicago, New England etc. etc. etc. I will agree that the Colts fit the statement however because they went from outside in Baltimore to indoors in Indy.
Truth is, as far as I am concerned, they have not been the true Vikings in over a quarter of a century. Four Superbowl appearances, and not one since they became a dome team.