Pretty much—since the modern Hebrew cursive (MHC) is based on the Ashkenazi cursive style that began to emerge in the 18th century, or thereabouts.
Here’s a fairly typical example of Yiddish handwriting:
And here’s an example of modern Hebrew cursive:
As you can see, the Yiddish cursive is more compact and the writer has a greater tendency to join up adjacent letters than the Hebrew one (both European influences).
Another common difference is that Yiddish writers tended to write the letter bet ב (b) like the number 2, whereas the typical MHC bet is different:
But for the fact that Yiddish is essentially a dialect of German, and its use of the letter א to indicate the /a/ vowel, and ע for /e/ vowels, a Hebrew-speaking Israeli could read it reasonably easily.