exult, etymological order

I checked etymology for exult in etymonline. Details are:

1560s, "to leap up;"
1590s, "to rejoice, triumph,"

from French exulter,
from Latin exultare/exsultare
"rejoice exceedingly, revel, vaunt, boast;" literally "leap about, leap up,"

frequentative of exsilire "to leap up,"
from ex "out" (see ex-) + salire "to leap" (see salient (adj.)).

I have following questions: pls help clarify. thanks

1. with in 30 years the meaning changes from “to leap up” to “to rejoice, triumph”? how this transformation is so fast?

2. from French or Latin? Is this possible to come both from French and Latin simultaneously?

3. frequentative of exsilire? what does this mean?

frequentative details from wiki:

In grammar, a frequentative form (abbreviated freq or fr) of a word is one that indicates repeated action, but is not to be confused with iterative aspect.The frequentative form can be considered a separate but not completely independent word called a frequentative. The frequentative is no longer productive in English, but still is in some language groups, such as Finno-Ugric, Balto-Slavic, Turkic, etc.

https://en.m.wikipedia.org/wiki/Frequentative