No. This information is not correct.
Tragically, these “Sisters” are traditionalist dissidents who are not in communion with the Holy See or the bishop of their diocese or the Prior General of either Carmelite observance; they obscure that information as they run a lucrative religious goods business. They reject lawful ecclesiastical authority.
Pope Saint Pius X, as every pope, has power over sacramentals. The pope may alter them…and he did regarding the wearing of the scapular, using the power to commute. While it is true that his motivation was especially because of the situation in the tropics, he did not limit the commutation to those in the tropics. Any Catholic may legitimately avail themselves of this grant. The scapular medal is perfectly valid although you will read articles by people who assert it is not.
You may find this article useful, although because of its age, it is dated as blessings are no longer reserved and indulgences are not attached to religious objects since the pontificate of Blessed Paul VI. It speaks of the distinction between large scapulars and small scapulars. Large scapulars are those worn by members of Third Orders Secular and, since the scapular is their proper habit, they must follow the norms of their secular order.
newadvent.org/cathen/13508b.htm
*The scapular medals
Since 1910 and the regulation of the Holy Office of 16 December of that year (Acta Apost. Sedis, III, 22 sq.) it is permitted to wear, instead of one or more of the small scapulars a single medal of metal. This medal must have on one side a representation of Jesus Christ with His Most Sacred Heart and on the other an image of the Mother of God. All persons who have been validly invested with a blessed woollen scapular may replace such by this medal. The medal must be blessed by a priest possessing the faculty to bless and invest with the scapular or scapulars which the medal is to replace. The faculties to bless these medals are subject to the same conditions and limitations as the faculties to bless and invest with the corresponding scapulars. If the medal is to be worn instead of a number of different scapulars, it must receive the blessing that would be attached to each of them, i.e. as many blessings as the number of scapulars it replaces. For each blessing a sign of the Cross suffices. This medal must also be worn constantly, either about the neck or in some other seemly manner, and with it may be attained all the indulgences and privileges of the small scapulars without exception. Only the small (not the large) scapulars may be validly replaced by such medals. *