Yes. “Old food" can be unsafe. Unrefrigerated prepared food is technically unsafe after being at room temperature for more than 4 hours. Bacteria grow at an increasing rate the longer food is around. At room temperature it doubles every hour. After 4 hours it can be at unsafe levels. Some foods with high vinegar content may be exceptions to this general rule. Artichoke dip isn’t an exception. Even refrigerated food grow bacteria but at a reduced rate. That’s why you can keep it up to a few days if it’s kept below 40 degrees.
If in doubt, don’t eat it. One bought with food poisoning, and you’ll be careful from then on. It’s awful. I have been told that once a person has had food poisoning, he/she is more likely to get it again because the bacteria can live in the stomach even after the symptoms are gone. I haven’t researched it to know if that’s true or not.
Most artichoke recipes contain milk products.
Spoilage occurs when dip is not refrigerated and micro-organisms degrade the carbohydrates, proteins etc. in the milk. Bacteria which grow well in such an environment include Streptococcus sp., Micrococcus sp., Caligenes sp. and Enterobacter sp., as well as dozens of others.
The answer is yes.