The existence of the Cascadia subduction zone wasn't established until the 1960s. The fact that it's active and generates occasional large earthquakes wasn't confirmed until the late 1980s or 1990s. So a station built with unreinforced brick in the 1890s will certainly require major reconstruction to meet modern building codes and keep operating, historic landmark status notwithstanding. Essentially, they will have to put up a modern internal structure (probably with steel) and tie the old brick walls to it (as, essentially, a non-load-bearing facade). Plenty of that going on in Portland and elsewhere in the PacNW for smaller properties, but $250m seems a bit light for something on the scale of Portland Union.