Yes, scale insects can infest camellia, though maybe not the same kind of scale. Best advice I could give would be to give your camellia the best growing conditions you can, do NOT over fertilize, keep well mulched. Keep an eye on the plant to catch a scale infestation before it gets to be bad. Oil sprays can quite effective in controlling scale insects.

Tea scale is probably the most common species on camellia, but others will find it tasty, too. Attached is a link showing a bad infestation of male and female tea scale on the underside of a camellia leaf. Image is much enlarged.

Here is a link that might be useful: {{gwi:514284}}

If you got rid of the old plants, you got rid of the scale insects, but they are drawn to conditions that are warm and humid with low air circulation, so if those conditions are the same they may come back. Scale insects don't kill a camellia overnight (they slowly sap its energy from the leaves) but it is easily treatable. I recommend using "Ultra Fine" which now comes in a hose-end sprayer bottle in garden sections of most big box hardware stores. Spray the underside of the leaves well (especially the lower branches where the scale is most prevalent) about twice a year or as needed. It works on hollys too.

Ultra Fine is a non-toxic wax substance that suffocates the scale insects. For severe infestations you can mix some malathion or other insecticide with the Ultra-Fine as needed. Another remedy is Cygon, painted on the trunk during growing season -- it is a systemic insecticide, and you don't need much.

Give the camellia a try!