Probably. When you buy a packaged of seeds it always contains a few seeds of a Monoecious variety to act as a pollenizer. Probable the nursery also included a pollenizer plant to ensure that the customer gets cucumbers. A gynoecious plant will have a few male blossoms, but in order to be productive need more male blossoms then the female dominant plants provide.
https://hortnews.extension.ias...