The Latin letters A–Z are used in Japan today and they each have a name just like in English. Take the first five Latin letters, A–E. Source: https://jisho.org
It is pretty clear that all except one variant of B (ベー) are from English. I don't actually know if that variant pronunciation is even used.
Surely in my mind the influence of Portuguese and later Dutch merchants and Dutch studies (Rangaku) would mean there was already a need to have Japanese names for those Latin letters, so it is only natural to assume the pronunciation/names of those letter would be based on what the Dutch themselves call them. E.g.,
And so on…
What is the history here? How come the English names for the Latin letters are so prevalent in modern day Japan?