I also never said they were going to go back to hitting at the rate of the first 13 games once Yelich returns. But adding your best hitter w/ an xwOBA of .460 seems pretty dang likely to lead to some positive regression for the offense as a whole.
Rhys Hoskins, for example, is someone with a lengthy track record and a career OPS of .841 while currently sporting an OPS almost 100 points below that....
Youngsters carry downside for sure as we're currently witnessing. But they also carry significant upside. I would bet on some figuring it out to a varying extent, and the ones that don't will get less and less ABs as the season goes on. Benefit of having the Brewers' position player prospect depth. You're not pushing all your chips on one or two guys.
Anyways, to answer your question. Is this the real Brewers offense? Unlikely. It's almost certainly somewhere in the middle between the first 13 games and the last several weeks. Which is about where it ranks overall now.