Many of the great British institutions where the use of Latin is (or was, until very recently) commonplace in worship suffered enormous loss of life in the two World Wars, and it may well be that Acts of Remembrance were translated into Latin a long time ago for use in the colleges of Oxford and Cambridge and in some of the great public schools. However, I am not aware of any of these Latin versions of liturgies for Remembrance Day. In the interests of adding to the liturgy of the Church of England a Latin version of a liturgy that does not appear in the pages of the Liber Precum Publicarum (the Latin version of The Book of Common Prayer, last published before the Great War), but has become a key element of the Church’s year, I have translated into Latin the Act of Remembrance devised by the Church of England in 1968. This is the short Act of Remembrance which will be familiar to anyone who has attended a short Remembrance Day or Remembrance Sunday service at a war memorial. There were also earlier Acts of Remembrance dating back as far as 1918, which can be viewed here on the website of the Prayer Book Society.
My Latin translation of the Act of Remembrance can be downloaded here: Actus Commemorationis.