Of course they can. Dictionaries are not the Bible. They exist to describe how words are used, not how they should be used. Words' meaning changes over time ("gay" meant "happy" in the 20th century, to use the tired example) and new words get added to the dictionary every day (most dictionary websites have little blurbs showing words they've recently added). Dictionaries have historically, and continue to, change in response to how people use words, not the other way around. If your entire argument rests on the dictionary definition of the word "protest" not explicitly mentioning that to be considered a protest, something must be disruptive, it's not a very good argument.
It also fails to consider that methods of convincing people who would rather simply ignore the issue to care about it that are not disruptive are few and far between.