> While baseline tweets remain stable throughout the year (with an exception in early 2022 coinciding with the Canada convoy protests (Soucy 2022)), hateful tweets increase dramatically following Musk’s takeover.
So the claim is that total tweets increase in early 2022. Total tweets in Figure 2 is the top orange line. There's a noticable spike approximately in April and another one around August. (That's going by my faulty eyes, so their claim that it's in March makes sense to me.)
Was that caused by the trucker protests? No idea. But there are lots of interesting looking spikes in this chart.