Yes, the same thought occurred to me too. It seems reasonable to think so. Yet I wonder …
It seems always to be the case that after deep samādhi the body is absolutely at ease and comfortable. This effect on the body seems to be the same regardless of the external temperature. In other words, the body is never cold when you emerge from samādhi. (Although feeling cold can certainly stop you from entering.) If we agree that the metabolism slows down as the samādhi deepens, then this in itself is rather counterintuitive. There seems to be something going on which does not fit with the normal connection between metabolism and the production of heat.
I would guess the missing factor is the power of the mind. A mind in samādhi has the ability to affect the body directly. The samādhi seems to stabilise and ease the body, as if it is pervading it with a benign and powerful energy. I tend to think the body temperature is directly regulated by the mind.
In the end I don’t know, yet it seems to me to be a real possibility. The world of samādhi is amazing and marvellous. Things happen that under normal circumstances would be impossible.