Is the phase shifting caused by analog equalization serious enough to require attention or even adjustment of some kind in a live sound reinforcement setting?
No. In fact when using EQ to enhance the tone of a track or fix problems with the track sitting in the mix, the phase shift is often part of the beneficial sonic change created by the EQ. In a live situation, the phase shift caused by EQ can actually provide more gain before feedback.
Phase linear digital EQs can actually sound a little strange becuase the phase shift goes along with the frequency changes both electronically and in our aural experience.
There are some situations where time alignment is critical, and phase changes brought on by EQ can be a factor, but generally a different caliber of microphone, preamp, etc. would be needed since all of those devices are not usually phase linear through their usable frequency range.