The two vulnerabilities are completely different. One is just that sunlight in particular hurts vampires. The other is that bright light, like sunlight affects drow. It's called sunlight sensitivity, but it's not limited to sunlight, so Barovia should affect them.
Except that the drow feature specifically calls out sunlight, not bright light. If they meant bright light, they would have said so. There are several monsters using either as their trigger - kobolds also have sensitivity to sunlight in particular, while shadow demons are hampered by any bright light - so the designers do differentiate the two.