St. Tikhon is certainly a saint.
It is important to realize that there was no idea of "ecumenism" at this time. It cannot possibly be said that St. Tikhon was an ecumenist. He was very strict in his confession and completely understood Orthodoxy and its importance. He died for the faith.
Also, at that time the Anglicans (and consequently the Episcopalians) and the Old Catholics were very interested in Orthodoxy. It seemed very possible that many large groups of Anglicans and Old Catholics might enter the Orthodox Church. This was not the result of ecumenism or "joint-theological dialogues", but merely an interest on the part of western-traditional Christians in the Orthodox Church. St. Tikhon, as a missionary, wanted to help facilitate such an interest in Orthodoxy. But he was by no means an ecumenist, that is, he did not believe that they were somehow also part of the Church.
Ultimately, though, the Anglicans and the Old Catholics did not join the Orthodox Church en masse. It is interesting that shortly after this both of those Churches became very liberal and grew further and further away form a traditional Christian understanding. The Anglican Church, for instance, now allows women priests and homosexual bishops. So they were given a chance to embrace Orthodoxy, but when they rejected it, they went off the deep end immediately.
In the caption of the picture above, it even points out that the Orthodox representatives are not dressed liturgically, as participants, but are there merely in their casual wear.