Does the type of preamplifier used for a piezoelectric sensor change its physical resonant frequency?
Yes it does effect the stiffness and thus also the resonant frequency of the sensor.
Liu, et al. in [1] show that for an closed circuit stiffness of \$Y_\text{open}\$, the short circuit stiffness \$Y_\text{closed}\$ is given by
$$Y_\text{short} = (1-k^2)Y_\text{short}$$
where \$k\$ is the electromechanical coupling factor. From this they compute the relationship of resonant frequencies:
$$\frac{f_\text{open}}{f_\text{closed}} = \sqrt{\frac{1}{1-k^2}}$$
As \$k\$ gets closer to \$1\$, the voltage amplifier can have significantly more usable bandwidth than the charge mode configuration.

\$k\$ values quoted in ceramic suppliers' specifications typically are theoretical maximum values. At low input frequencies, a typical piezoelectric ceramic can convert 30 - 75% of the energy delivered to it in one form into the other form, depending on the formulation of the ceramic and the directions of the forces involved.

 Piezoelectric Constants  from American Piezo
[1] Liu, Weiqun &amp; Feng, Zhihua &amp; Liu, R &amp; Zhang, J. (2008). The influence of preamplifiers on the piezoelectric sensor's dynamic property. The Review of scientific instruments. 78. 125107. 10.1063/1.2825404.