Hardly, young friend. Shambhala derives from the Kalachakra (Wheel of Time) Tantra, perhaps the most profound teaching of Vajrayana Buddhism. It was in the kingdom of Shambhala that Lord Buddha taught the Kalachakra to King Suchandra, one of the Rigden Kings of Shambhala. Shambhala is a real place but not one that you or I can visit. In fact, I visited one of the portals to Shambhala in Mongolia, but only those of sublime realization can actually go there. And no, I'm not making this up. There are Pure Lands, they do exist, but you won't find them on any map.
Shangri-La is simply the Westernization of Shambhala used by James Hilton in his book Lost Horizon, a novel based on the legend. Unfortunately a lot of the Western interest in Shambhala is based on the misconceptions or fabrications of spiritual wannabes like Madam Blavatsky and Nicholas Roerich whose stories of Shambhala were mainly based on their own delusional thought systems. Thus much of the information floating around on Shambhala in so-called New Age circles is simply wrong and definitely misleading. In such circles it does resemble Atlantis or Lemuria and is a crock. Don't believe any of that stuff. But that doesn't mean that there isn't something to the Shambhala legend.
For a different twist, see Chogyam Trungpa Rinpoche's Shambhala teachings which aren't centered so much on the Kingdom of Shambhala but rather Shambhala as an example of enlightened society.
I am so glad you have mentioned Nicholas Roerich. He tends to be ignored because he didn't come and spread himself across western society like MPB but stayed in that strange house at Naggar near Manali, in the Kulklu Valley, studying and painting, and, above all, working for peace.
Anyone who hasn't come across this wonderfully odd individual, here are some links:
I remember I read somewhere online where the Theosophist author seemed to realise in the end, after meeting with the entrance to Shangri-La, did he realise that it's appeal was not in reaching the place - but rather, the journey itself.
I seem rather surprised by the concept... I was thinking it as some form of metaphorical stuff... Is it even possible that somewhere out there can a civillisation remain so remote? Although I have heard of HHDL speaking of it as being in a "parallel universe"-like thing, and another source using Tibetan culture to suggest waterfalls as being the entrances to such lands.
It was no disappointment, on meeting the Dalai Lama, to find that he looked nothing like Samm Jaffe! But then, I look nothing like Ronald Colman, either.
I definitely find Roerich much more appealing than Blavatsky, Simon. He was quite an interesting character, despite his bizarre beliefs. Blavatsky, on the other hand, was just a con artist, imho. Had little or no spiritual insight that I can detect. She reminds me of the packs of posers that infest Sedona pretending to be so spiritual and "enlightened". Mainly they're hungry ghosts who desire spiritual insight but have no clue how to get it!