Hmmm.... My update history shows the following, so it's possible these updates came out earlier and the legend in the Updates window simply shows the date of capture not the date of release:

New Surface Pro 3 Firmware Update - June 6th, 2017-sp3-firmware.jpg

Notice that on my SP3, the release numbers for the two most recent firmware updates are identical to the ones showing in your post. But notice further that my install dates are back in May, well before June 6. Interesting, eh?
Thanks for the heads-up nonetheless!
--Ed--

PS: Upon further reflection, I now understand that because my SP3 is on the Insider Preview for Current Branch, I probably got the firmware updates before they were released to the general user base outside that preview program. Now, it all makes sense. I leave my original post unaltered to inform other readers that Insider Preview users may see firmware release dates that differ from official, general release dates. I didn't know that, so I assume others may be likewise unaware of that distinction. Hope that's OK.