Yes, what I was going to suggest about the rarity of a healthy butternut tree.

In Ontario there are a number of rules about the tree and perhaps a heathy tree is worth a lot to keep seed from that might be resistant to the disease.
There is an active group seeking healthy trees to look for genetic material.

This gives the rules in Ontario but a reputable logger or forester would be able to tell you more for your area

https://www.ontario.ca/page/butternut-trees-your-property 
 

The rules

Before you do anything, you must:

• have a qualified butternut assessor determine the health of the tree
• send the assessor’s report to a Ministry of Natural Resources office 30 days before the proposed activity
• allow ministry staff to visit the site during the 30-day period, if asked

After the 30 days, you can remove or harm:

• trees in the advanced stages of disease (category 1) as identified in the report
• up to a maximum of 10 retainable trees (category 2) as identified in the report – but you need to register with the Ministry of Natural Resources and follow additional rules (e.g. plant butternut seedlings)

You cannot remove or harm trees that appear to be resistant to butternut canker (category 3 trees).