The maglev system is very impressive and has been refined over the last 22 years. In near term, the newly formed Cascadia would need to be budget conscious. Maglev would require a complete replacement of the physical plant of the railroads in the region. Neither a cheap or quick project.
Funding directed to plant enhancements to allow higher speeds on freight and passenger traffic would be a faster and more reasonable short term solution. Longer term when things are stable a secondary passenger only maglev line could be built form say Eugene to Vancouver(BC).
Restoration of some discarded short lines would also be beneficial to the newly created Cascadia such as the line to North Bend. Oregon's only deep water port.