I would agree “long term” does not meet the definition of a payment period trigger term. The commentary clarifies that a specific period of time or payment term.
Reg Z Comment 1026.24(d)(1)-2 says:
The number of payments required or the total period of repayment includes such statements as:
A. 48-month payment terms.
B. 30-year mortgage.
C. Repayment in as many as 36 monthly installments.