Do an internet search and you will see that there are plenty of ways for a FSBO to advertise.

Facebook Marketplace and in the Facebook groups. There is one in my county for Buy/Sell/Rent real estate and I have seen FSBOs post in it.

Craigslist?

The FSBO market is not, nor has it ever been, a market I tracked, followed, or cared about in any way. 

Hi, Bob.   I was not aware that Zillow was going to stop letting FSBO's advertise.  I see single family houses, 50 FSBO on Zillow for nearby Greenville, SC and 25 houses for nearby Asheville, NC.  Maybe they got in before the cutoff date?

Bob,

Z is so far off our radar screen that for our clients, they are immaterial and irrelevant...LOL A

We still have FSBOs on Z in my area.  Just checked.  5 of them in my city alone and the "List your home for sale" portals are still up and working.

I have no idea Bob.   And sorry I missed your preso......couldn't be avoided.

Is that so?

Craigslist & eBay! 😂

Interesting. We do not see many FSBOs in our area.

Didn't know that but that's going to be an exposure problem. 

Fascinating as they could not monetize it so they cut it loose. FSBO remains agent bait...

Facebook Market Place.
It is not rocket science to understand how people find the information they want. 
And, the agile real estate agent will develop a means to help these FSBO with their problem.
AND of course those direct buyer operations are dancing in the street. 
Who knows, the consumer may actually realize they can create the choice they want.
I trust everyone on Active Rain knows YouTube is the #2 search engine in the world. I"ve sold lots of real estate via YouTube. So can the FSBO.
The agile agent would be wise to troll YouTube to be aware of the 'hidden inventory' and take action to interceptt these innovators. (Hint: FSBOs can not keep advertising off of their videos any more than we can.) This is a better environment for the real estate agent than FB.

FSBO's were never a niche for me when active. 

Do not pay attention to the FSBO market, do not see many in our market place.

I did not know that either. What is the cut off date?