Does involvement with a children's aid society automatically mean supervised parenting time will be ordered?

No. Children's aid society involvement, by itself, doesn't automatically trigger supervised parenting time - that's a specific restriction a family court, or the parents by agreement, puts on an order, and it has to be justified by the actual concern in your case, not by the mere fact that a society has been in contact with the family. Many CAS files close with no protection concern substantiated at all, and a family court is not required, or even likely, to impose supervision just because an investigation happened.

What matters is what the involvement was about and what it found. A serious, substantiated safety concern - particularly one involving family violence or a direct risk to the child during parenting time - is the kind of finding that can lead a court to order supervision, at least temporarily, until the concern is addressed. A closed file with no findings, or an investigation into circumstances unrelated to parenting time itself, is far less likely to lead to that result. If supervised time is being proposed against you, ask what specific concern it's meant to address and get legal advice about whether the evidence actually supports it, since supervision should be tied to an identified risk, not imposed automatically.