I don't know what your plan is concerning gravel.
A skinny tire can handle a little. For example, there are two "gravel" races in Colorado that far predate this gravel craze, Boulder Roubaix is your classic flat gravel course and Koppenberg is a nice circuit with a technical rutted out climb every lap. Me and thousands of others over the years have done these on 23's. Just unwilling to bog down our bikes with wide tires.
I'd imagine events like this are ridden on 28-32 tires now, given what we've learned about tire width and speed. Still this puts you easily in the realm of a road bike.
I can't even count the number of times I did a short section of gravel, sometimes rather rough, on 23s to make a nice loop without backtracking. It can be done and is definitely not a guarantee for flats.
I rode The Crippler on a classic road bike with 28s the first time I did it. Much nicer on the climbing and roads but a little sketchy on the wild decent. I survived.
Once I got a real gravel bike, I used it as a mountain bike but for much longer distances and used dirt roads to connect more singletrack. Totally different than riding straight lines on smooth gravel roads.
What I'm saying is that yes, it's totally possible to take a proper road bike on a little dirt. Look at your objectives and decide. If it's mostly road with some dust and gravel thrown in, a race bike that can fit 33's is more than enough. If it's long days on gravel, with Jeep roads, singletrack, and rutted out washboards peppered in, you'd probably benefit from a gravel bike.