“The date of Yom Hashoa was chosen because it was the date of the start of the Warsaw Ghetto Uprising”
Except that it wasn’t
It is hard to determine an exct date as there was some fighting in January of 43′. Most historians Consider April 19 43′ (Erev Pesach) as the start of the “official” uprising.
It was considred that 14 nissan be yom Hashoa but that idea never gained much traction.