I don't buy it. Any academic presentation of a subject includes the limits of current knowledge. Maybe this is not emphasized enough, but it's a matter of extent, not a qualitative refusal to acknowledge ignorance.
A great example is that mainstream academic economists are very open about not being able to explain why monetary stimulus works. At one point (maybe this goes back to Keynes or even further) people attributed it to sticky prices. But current research cannot come up with a reasonable mechanism based on sticky prices that would explain the magnitude of the effect of monetary policy. Currently people accept that what we observe on the macro level cannot be explained on the micro level.
A great example is that mainstream academic economists are very open about not being able to explain why monetary stimulus works. At one point (maybe this goes back to Keynes or even further) people attributed it to sticky prices. But current research cannot come up with a reasonable mechanism based on sticky prices that would explain the magnitude of the effect of monetary policy. Currently people accept that what we observe on the macro level cannot be explained on the micro level.