The pan rail of a Y has dimples or flutes, which prevents a flat reinforcement from being used, which would make a similar item expensive to manufacture. That would be compounded by the fact that it is a small market (small quantities are more expensive, per unit, to manufacture than large quantities).
It would probably require someone with a particular interest in the Y to manufacture, and a real need for it. Sealing the oil pan doesn't seem to be a significant problem.
Lawrenceville, GA