Only if there was no bottom to start with.
The guitar shouldn't be providing the "bottom end" anyway so when the rhythm parts stop and the solo begins, the mids and top, ie guitar frequencies, should be the only thing that changes.
I have only seen Geddy Lee briefly, but long enough to know that I'm not a fan of his style. The big trios from back in the day, Cream, ZZ Top, Jeff Beck Group, Hendrix and even Led Zep, none of them "filled" up the sound with bass when the guitarist started soloing.
If the bass needs to fill out the sound during solos then something is fundamentally wrong with the sound of the band in the first place.