I put walnut leaves on my garden beds for 2-4 weeks, do I have to take off the first layer of soil?

Hi there,
we made the great mistake of mulching with unknown leaves and then discovered they were walnut. They have been on one bed for around 4-6 weeks, on the other for maybe 2 weeks. AI has informed me that it would be best to get some of the topsoil off to make sure no juglone that might have leached is left. What is your human advice on this? This was such a mistake, I am so sad
Thank you in advance!

Google tells me juglone breaks down quickly in soil (slower in actual wood), so should be clear again in a month or so. And your levels are likely to be very low anyway from a temporary application of leaves as a mulch. I'd just leave it until spring for planting. Maybe mulch with some other material, which will promote more biological activity in the soil and speed the breakdown.

At my last house, two of our big trees were black walnuts and we mulched with all the leaves that fell. Never had a problem that I'd trace back to that.

Google also tells you juglone tolerant plants.   If you look it is mostly what you want to grow so it may just suppress the weeds so is beneficial.

I think it will be fine, having built hugels under the drip line of a walnut and having all but the most sensitive plants (tomatoes) seem ok. It was a very old walnut that rarely produced many nuts, the husks of which seem to be the most concentrated with juglone, along with root exudates. It would be a good experiment to plant it with half juglone tolerant plants, and the other half intolerant plants, then observe and share the results. Gaia’s garden is a good resource for juglone sensitivity and much more. Thank yoi for getting this experiment started for us all!

black walnut's allelopathy is a myth.
https://pubs.extension.wsu.edu/do-black-walnut-trees-have-allelopathic-effects-on-other-plants-home-garden-series

As I have learned, the chemical in walnut leaves is called juglone, which can harm some plants, but not all.  
I would simply remove the top layer of walnut leaves, and mix in a good layer of compost.

Shahar Goldin wrote:black walnut's allelopathy is a myth.

That was an interesting read, for sure, and I'm sympathetic to that stance because it supports my own observations. But I think "myth" is a little too strong. The paper cites a bunch of reasons not to believe but also says that the research needed to really know just hasn't been done.

In fact, I'm going to pin that PDF here in case it ever vanishes from the WSU webpage.