Should acne-prone skin avoid silicone in skincare?

Not automatically. Silicones such as dimethicone are also used in moisturizers, and their presence alone does not tell you a product will clog your pores. I would only remove a silicone-containing product if that specific formula appears to be a repeatable problem for the individual.

Silicone is not automatically the cause of congestion

Look at the finished formula and your actual response. A repeatable reaction to one product is useful information, but it does not mean the whole ingredient family is unsuitable.