I've laught about the "I'm amazed Christmas advertising hasn't started already".
I don't know about England but in France, it starts usually at the end of September.
Starting Christmas advertising so early is, to me, the best way to get people bored of the celebration before it was even the time to think of it (I think there are many other Christians celebrations than Christmas, though I'm muslim and thus I know nothing but the very basics of the Christianism).
If I were you, I'd see it as a good thing that your holidays have not been stripped of all meaning by corporations and atheists - transformed from a sacred time of worship in to an excuse to sell greetings cards earlier and earlier in the year (I'm amazed Christmas advertising hasn't started already). If the penalty for this is that you can't make a topic on these forums, is that such a high price to pay (I'd gladly pay that price to get the meaning of Christmas back for everyone).
Anyway, it depends on the CONTENT of the post. In many western countries now, Christmas is a holiday celebrated by non-religious people as well as religious people. They have removed all religious aspects of it, and made it just about presents and consumerism. In that regard, many "Christmas" threads are not religious. If you can apply the same view to Muslim holidays, and show that while they were historically religious but now no longer have any religious meaning, and are for the most part just a random party for people in the middle east, then they are again not a religious topic.
That has always been my view, but every one I've seen has mentioned the religious aspects of the holiday within the first few posts. Neither one of the topics you linked to mentioned Jesus, God, Mary, Joseph, or the Bible.
Remember - the rule is no religious content, not no content at the same time as some people might be doing something religious.
Threads from 2008 (as they both are) are not good examples of threads that follow current rules. The forums rules evolve and change over time in response to what people are doing and what we feel is and is not appropriate. If you can find an example from 2013 that is different, but a thread from nearly 6 years ago is not at all bound by the current rules, only what were forum rules at the time.
So we apply CURRENT rules as consistently as possible, but we aren't going to back-date rules and apply them to every post that ever happened in the past.