The prayer was specifically for them to have a holy and spiritual Ramadan, not to be “good Muslims”. It implies at least as much if not more than it states. It means being closer to God. That also means perfecting one’s understanding of Him and that leads logically to only one place, Christ’s Church. Perhaps you would have preferred more direct language. I tend to think one attracts more with honey than vinegar, and that respect for a religion encompassing 1 billion people is rather wise and prudent.
The Mass is a public worship, even Muslims are free to attend. Some may in fact do so out of curiosity, or accompanying a Catholic friend. I should think it behooves us to treat them with respect withou contradicting our own faith. A carefully worded prayer such as this attempts to strike that balance.