All depends, if it goes through the prop (worst case scenario) and THEN into the windscreen, like birds have done (they can take the prop out while still remaining intact enough to go through the windscreen) it could be a problem. Or, if it just takes out the prop, and now the out of balance prop rips the motor off it's mounts, and besides coming down you are also left with a out of limits center of gravity, usually leading to an unrecoverable spin. That has also happened after large bird strikes.
I have "interactions" with birds often, the last was a couple months ago. A turkey buzzard, I saw him in plenty of time, I was going the usual 80 mph or so, and he seemed to see me. But sometimes, these large soaring birds get territorial, they can get ignorant, this one did. He quasi attacked me, just basically letting me know it was his sky and I was intruding (true enough, but hey I was just trying to get back to MY nest), making a point to eyeball me as we passed each other about 40' apart. Getting the pig eye from a large soaring bird is awesome, done it before, there is no doubt they are the masters and you are not, it's an honor to get eyeball to eyeball with them. But this day, the bird's response struck me as kind of pissed off. For some reason, I heard myself say as we passed, and I actually said these words, "HEY MAN....WHAT'S YOUR PROBLEM?" It wasn't scary, as we both knew each other were there, he was just messing me, flipping me off as we passed as it were. Then I realized how funny it was, me talking to this bird, with no one else in the plane, like it was some kid on my lawn. Drones are spookier, birds got their act totally together and are super good in getting out of the way, drones are butt stupid.