Very big improvements so far, especially in the simplifying of the text and overall cleanliness.
I do want to point out a few things though, and after what youΓÇÖve said about changing up such a huge amount of thumbs you might not like hearing this, in which case, try these on a small batch of thumbnails first.
first of all the colour of the text background. Yellow and red are very specific to Nick NimminΓÇÖs style of thumbnail branding. whenever I see other people go with that style of thumbnail text banners (and a lot do it, it works well visually, which is why a lot go with it) but whenever I see that, especially in those colours, I canΓÇÖt help but think Nick Nimmin.
Luckily youΓÇÖre in a differant niche because if you werenΓÇÖt there would definitely be comparisons made. IΓÇÖd experiment a bit more with the colouring
speaking of colour. The blue of your background IΓÇÖm not a fan of. The lighter blue trending towards purple isnΓÇÖt so bad, but the bold blue I just canΓÇÖt stand from a design stand point. It reminds me too much of Microsoft publisher and Microsoft PowerPoint, again, IΓÇÖd do more experimenting with colour, you could even play with subtle texture or even light patterns for the background to make it slightly less flat
Thirdly, IΓÇÖm not sold on the black and white photography. From a design standpoint and ΓÇ£using colour as storyΓÇ¥ black and white often associates with depression, sadness, anxiety, serious stories. The only time I really see black and white photos being used is when a sad depressing serious story is being told, and judging by the titles, that seems to be far from the case. IΓÇÖd go back to using colour photos personally.
on the plus side, my criticisms are only colour theory based, your composition is a lot better and youΓÇÖve really tidied things up. IΓÇÖd just refine your colour choice and selections. The colour of the text banners run a very fine line to looking like a Nick Nimmin copycat. I know you were inspired by him rather than wanting to copy him, but first impressions in the space will veer towards that kind of interpretation.
These are very much on the right path though!
So study pattern and colour theory some more ΓÇ£color theoryΓÇ¥ in google should show some graphic design articles around topic of colour theory. And ΓÇ£ΓÇÿpatterns in designΓÇ¥ ΓÇ£pattern designsΓÇ¥ and. ΓÇÿPattern as a design elementΓÇ¥ whoΓÇÖll help you continue your learning in the thumbnail space
YouΓÇÖre doing a great job with your improvements though