I have mixed feelings about this one, although it's great to see the Baker Street detective having his own Tarot, I have serious doubts as to how useful it will for most readers. Will a querent be instructed to go away and read the complete SH canon before they can have their question answered? More interesting for me is the possible link between the Tarot and a metaphysical layer in the stories that some commentators believe was one of Conan-Doyle's motivations for writing them.
Under this model the choice of the Reichenbach Falls (a series of waterfalls in Switzerland) would seem to be an excellent fit for the 'Tower', since there was also a notable C19th German chemist, Baron Carl von Reichenbach, who proposed a vital energy or life force which permeates and connects all living things, which he named the 'Odic Force'. Waterfalls and fountains are a common esoteric symbol for the inflowing (and outflowing) force of life, and some interpretations of the dream of 'Jacob's Ladder' view the 'ladder' as a Ziggurat (a step pyramid) upon which the angelic beings are ascending and descending. On the Sixth Day of the 'Chymical Wedding' Christian Rosenkreutz finds himself in a Tower, with a ladder which is twelve-foot long and a fountain nearby which is turned off so that it runs no longer. The hole at top of the Tower is opened, and a bright
stream of fire shoots down a tube, passing into a prepared body. He then remarks that the point of this process is to bring the soul (stream of fire) into the body.
Regarding Conan-Doyle and the Tarot, I've never read of him owning or using the 'Wicked Deck' but in 2009 the Edinburgh College of Parapsychology found an "occult Victorian device" which responsible journalists then tried to exploit as having a tenuous link to him.
Sir Arthur almost certainly didn't own or use the one shown in this article because it is a c1932 'Two Worlds Telepathic Spirit Communicator' dial plate, which wasn't made until after his death, and was probably given as a gift by Richard Boddington to ‘The Edinburgh Psychic Centre College and Library' (as the Edinburgh College of Parapsychology then was) on it's opening day in September 1932. However, given his interest in Spiritualism, it is entirely possible that Conan-Doyle may have owned or used the c1900 'Braham & Co Telepathic Spirit Communicator' of which the 'Two Worlds' one is a later re-branding.