Might be true? It is true. Timo was what we call the black sheep of the family. In the 1950s, he married a butcher's daughter, had two kids, and she died young. He had no real relationships with his two kids until much later as he spent a lot of time in a mental hospital.
Alexander became the heir only after the death of Prince Johannes of Saxe-coburg and Gotha, who was the son of Mathilde. He was the designated heir when it became apparent that Max Emanuel and Anastasia were unable to have children, and Albert's marriage was morganatic.
In 1997, Max Emanuel, Anastasia, Albert, his wife, Prince dedo (and also signed for his brother Gero and their stepmother, Virginia), Timo's widow and the three sisters of Max Emanuel, signed a family pact, legal document that named Alexander as heir, and head of the family. Timo's children were not party to the pact because Rudiger and Iris have never had dynastic rights.
Alexander enhanced his position by marrying Gisela of Bavaria. He is well educated and a successful businessman. Rüdiger has been in jail. his first wife killed herself, and has never been considered a dynast.