Yes, it does. FiveThirtyEight's modeling includes sources of uncertainty beyond just the margin of sampling error of the individual polls.
They've tallied up how much the polling consensus erred for past elections, and have found that while it is not consistent which direction the polling consensus will err for a give election cycle, it is possible to quantify what is a typical size of polling error. Or to put it another way, which methodological shortcomings matter changes from one election to the next, but that doesn't stop you from estimating how big an effect it is likely to have.
Assuming that the polls are likely to be collectively wrong by some amount is why the FiveThirtyEight forecast's probability distribution is so wide, with their 80% confidence interval for Trump's electoral college vote total currently spanning roughly 120 to 280.
(They also include uncertainty factors for how much the true state of the electorate's opinions could shift between now and election day, but those factors are fading out of the forecast model as election day approaches.)
Not too surprising. Many Hispanic in Florida are Cuban, and republican. There are two Cuban US senators (Marco Rubio and Ted Cruz), they are both republican.
Hispanic people are not a single voting block, due to their diverse cultural backgrounds (black, white, Indigenous South American, mixed, rich, poor)
I think 538 does take this into account in terms of the uncertainty, which plays into their probabilities. I know they certainly talk about this.
This year, there are some truly weird things happening. For example, Trump is losing ground along seniors while gaining ground among non-white voters. He is polling 10-20 points better among Hispanic people in Florida, for example, than in 2016. https://fivethirtyeight.com/features/trump-is-losing-ground-.... Trump is significantly outperforming Romney or McCain among non-whites, and significantly underperforming among seniors. Polls do lots of adjustments based on assumptions about e.g. voter turnout by race, and I don't know if pollsters have really gotten their arms around this situation.
The explanation of the "16% chance Trump wins" got a little unscientific in the media last time. To be precise, that's the probability that Trump wins based on the statistical distribution of the different polls and the margins of error within polls. (Roughly speaking, it's "measurement error.") It does not address the possibility that there are systematic methodological shortcomings in the polls. Both things happened in 2016: there was a significant chance of Trump winning anyway, but there was also systemic errors in assumptions regarding low-propensity voters, voters who haven't gone to college, and undecided voters. Pollsters have seemingly fixed those errors, but that doesn't mean there aren't other ones.