Can ad networks still target ad campaigns using identifiers such as phone numbers, emails, names, etc.?

This depends on the ad network, and whether the data is available to them in a first-party context.

A walled garden network like Facebook will likely have no problem continuing to use their first-party data about their own end users to target ads. However, other networks that don't have their own store of first-party data for targeting won't have that option (for example, re-targeting campaigns where the audience was generated somewhere else and then imported into the network's system as a list of IDFAs).