Grindr usage spikes during ANY major event like those. You could have a Lesbian (is Grindr just for men? I'm assuming it is else my example is not really working) conference and the usage would spike. It's just the population of the city increasing due to the event. There are journalist, and countless people flying in that are their to support the event infrastructure that don't actually belong to that events "group". And, ya know, literally people driving/flying into the city, and staying in the city, to protest the event.
Sorry. I'm being autistic. There are definitely gay Republicans on Grindr. But it's not really a useful statistic looked at in a vacuum.