I don't think
Phyllis is necessarily too old fashioned. It's just hard for me to imagine someone under the age of like 20 with the name. I'm pretty neutral about the name. I'm pretty neutral about
Evelyn too, but I don't think I'd use the two together.
Actually, I'd probably be more inclined to use
Evelyn instead of
Phyllis just because I like the nickname Ev more than the nickname Phyl.