Yes, because it wasn't a gift. However it was a reimbursement for the expenses paid* and it was received because of the service your grandfather provided as a union worker. If not, you would not have received a reimbursement from them.
- *The money used by your grandmother (or others) was from income that was already taxable funds.
The answer you cited above is the best resolution as long as you offset the income only to the extent it was used to pay for the funeral expenses. As noted in that answer, there is nothing to indicate this should be income, but the union believes they are required to report it which has likely not been done in the past. Follow the instructions below.
https://ttlc.intuit.com/replies/5963424
