The short answer to this is "yes" if by that we mean some of these voters are willing to express a preference for Biden over Trump in 2020 trial heats. It's difficult to interpret Biden's significant leads over Trump in states like Michigan, ,Pennsylvania and Wisconsin in any other way.
As Martin Longman notes in a piece on the Political Animal blog, it makes more sense to reason from these polls--which apparently now include polls conducted by the Trump campaign itself--than from articles that quote non-randomly selected working class Trump voters saying how much they still love the President. The latter of course prove nothing other than that such voters exist and the reporter found some.
That said, if by winning we mean in the stronger sense that Obama-Trump-Biden [trial heat] voters are for sure going to vote for Biden over Trump on election day, 2020 if that's the matchup, then of course we can't really say. But it seems promising that at this stage, some of these voters are at least open to going back to the Democrats. As Longman rightly expresses it:
"Ultimately, we cannot know if Biden will be the nominee, nor whether he can win back an appreciable number of Obama/Trump voters, but those aren’t the questions we need to answer right now. First, we need to understand which states are winnable for a Democrat if he or she doesn’t make inroads with white working class voters. Then we need to figure out if there’s an Electoral College path to victory in that scenario. If there is not, or if it looks like a very long shot, finding a challenger for Trump who has “strong support” in these communities will then be vitally important."