No, for several reasons.
First off, there weren't 130,000 people there. The venue holds 20,000 people (not 30,000) and was near, but not at, capacity.
Second, 130,000 is a drop in the bucket. About 130 million people cast ballots in the 2016 election, meaning that 130,000 (which, again is not the number of people who were actually there) would be only one tenth of one percent of the total ballots cast. Even in Florida it would only be about 1.3% of ballots cast in 2016. And 2020 will probably see even more people vote.
Third, the hypothetical 130,000 attendees don't necessarily indicate that Trump is popular. All it indicates is that 130,000 people wanted to go to this rally. It doesn't indicate if these are new people who have been won over to Trump, old supporters, people who don't plan to vote, or how this relates to other voters.
Fourth, while Democrats would clearly want to win Florida, it's not strictly necessary for them to win. If they win back the rust belt states which Trump flipped then they will win, even if he takes Florida. And the polling, including internal Trump polling, all indicates that Democrats are, currently, likely to beat Trump in those states. Also, the fact that Democrats swept all statewide races in those states in 2018 shows that Trump could be in deep trouble. Of course, the attendees might not all have been from Florida, but if we assume that they came from other states as well then that further reduces the importance of their numbers.