Definitely correct. He'll run slower than expected. For one thing, he's not a 45.94 guy. He ran 45.94 one time in optimum conditions in a race he had targeted for years.
Warholm and Femke Bol maximize their ability level in 400 hurdles by using those techniques described by Edwin Moses...using left leg lead every time and running on inside of lane line. The left leg lead in particular is a huge edge, if you watch the videos carefully. Not only is the angle around the bend already superior via the landing point but the trailing right leg comes across the barrier right to left, shifting your weight and further slingshotting you in the preferred direction. It's really glaring that the 400 hurdlers who lead with their right leg around a bend have that momentary pause where not only are they landing in the center of the lane as opposed to left side of lane, but their torso and momentum are facing forward instead of ideally angled left. Quite the waste. It basically requires one extra step to recover and maximize.
In total it makes Warholm's flat speed appear slightly greater than it is.