It's better to actually refer to manulife's brochure which I did provide the link to if you want more info to assess it. I don't find it weird. The brochure's explanation is pretty plain.
Did you see the brochure at all?
If entire life does not mean 99, then the only other meaning is the literal meaning which means it can continue paying till the child dies even if that is 110 years old.
I went to take a look at the online brochure.
Example 1: 3 generations plan.
Single Premium = $499,800
Insured starts at 45 years old
Payment starts at 50, projected at $1,470 per month
for 16 years
At end of 16th year, policy transferred to child who is 35, the child will continue to receive the projected $1,470 for the rest of child's life.
When the child dies, a lump sum will then be paid to the grand child at a certain projected amount.
Key is the insured is paid for 16 years but the child is covered for life and grand child gets a lump sum.
Example 2: 2 generations plan.
Single premium = $499,800
Insured starts at 45 years old
Payment starts at 50, projected at $18,214 per year (or $1,518 per month) up to 99 years old.
When insured dies, the child gets a lump sum. The sum is calculated based on certain formula given in the brochure.