This campaign doesn't change the reason why peoples are searching for bad things about Romanians. It's just fixing a symptom but not the source of the problem.
Yes and no - I'll often note what Autocomplete prompts when I'm doing a search. Negative autocompletes may impact my perception of something when doing a related search (say, "Romanian holidays" and at "Romanian" autocomplete throws up some of the negative terms in the OP).
So it lessens the spread of those negative terms. As you point out, of course, it doesn't change the (far more important) source issue of people believing those stereotypes before going into Google.