Struck is simple past, stricken is the past participle. It’s the same pattern as “write, wrote, written.” Striked through is not “right” here, but at the same time, it’s a totally valid way to say it in various dialects, so that’s right enough for most purposes. In my dialect, workers might have “striked,” but that’s also nonstandard.

Just a regular linguist, which means I’m obligated to make it really clear that prescriptivism is bullshit, but does really simplify things for non native speakers