Yeah, I wish I had nothing but anatomy to worry about.
Honestly, I know everyone will say, WHAT ARE YOU TALKING ABOUT!? But I regret not studying at least a bit of anatomy before med school. I doubt I would study anything else, but jumping in with tons of material all at once while taking 3 other med classes is kind of ridiculous. I wouldn't go all out and ruin my pre-med school time, because that time is precious and I'll never get it back, but if I had the time, I would have sat down with Gray's and read a bit of it, even a couple hours a day for a month. At least get yourself in the mindset for learning this stuff.
Obviously it depends on how much free time you have before school, but if you have enough time to both read and go and hang out with family and friends, I'd just go for it. Don't expect to memorize or really learn the stuff, but just get in the habit of dealing with the material. I'm still amazed that 2 months in, I'm almost done reading this whole book and memorizing a ridiculous amount of it.
Also, to be clear, most undergrad Anatomy courses are a joke compared to med school anatomy. Maybe if you are at a school that has a grad level course or a "med school light" level course, it might be useful, but most of the anatomy taught at my undergrad was the most basic of basics.