As acoustic music relies on shifts in dynamics, is dynamic range compression used by recording engineers in classical music recordings?
Yes, although there is a school of using only two microphones and no processing. Generally, for records and TV music the dynamic range is reduced. It is of course dependant on the material, but if you look at symphonic works they often have a dynamic range much larger that a typical listener, equipment and surroundings can accommodate.
It is done, at least in the recordings I have done and the ones I have been involved in, more by "riding the faders" than by using a compressor. It might be that there are better compressors available, but the ones I have tested tend to give an unwanted signature modification of the sound. A limiter might be useful to contain some of the very strong accents, say that extra strong bass drum beat at the end of a symphony. In a DAW I instead use volume automation. The low pitched lyrical section will get a bit of volume boost, the fortissimo section will get a bit of volume decrease. How much to boost or decrease is all about taste. If using several microphones, a recording session today may use 50 or more microphones, you will probably raise an instrument mic slightly when playing a solo and turn it lower otherwise. This as well tends to reduce dynamic range.