He says, if a person is sick and expects to recover.

Meaning after a year or two or more, should he make up Ramadan later with expiation or without expiation? No, without expiation.

There is no expiation required, only making up the fast. His guardian fasted on his behalf, he says: if he dies and he still has fasts to make up, most scholars say his guardian may fast on his behalf if he wishes.

It is not obligatory for him, but if he wishes, because the Prophet ﷺ said: Whoever dies and still owes fasting, his guardian should fast on his behalf.

Some scholars apply this to fasting that was vowed.

Most scholars apply it to all types of fasting, so his guardian may fast on his behalf, and if his guardian does not fast on his behalf, there is nothing required.

No, no, there is no expiation.