If I understand correctly Biologos would prefer the term evolutionary science Christians. Evolusionism is regarded as the atheistic dogma that there is no need for God.
The term evolutionary science Christian is onlu used in Biologos. Most theologists writing on evolution, especially the Catholic ones, use the term theistic evolutionism and theistic evolutionists.
This is in line with the terms creationism, intelligent design evolutionism, atheistic evolutionism and agnostic evolutionism… I do not think that it will confuse people as the terms describe exactly what they mean. The term evolutionism is to vague to use instead of the above terms.
I would appreciate the insight of Christians interested in this topic