I don't find having varying levels of data and confidence about the likely future directions of a project to be "clutter", nor do I find they tend to complicate whatever I'm trying to develop right now. On the contrary, I often find it useful to have more context and frame of reference about what I'm doing, even though often I may choose not to act on that knowledge immediately for much the same reasons that others here are arguing for always following YAGNI.
Please remember that my argument is not that you should always try to anticipate future requirements or over-engineer designs to cope with every hypothetical you can think of. My position is merely that you should weigh the costs of acting unnecessarily now against the costs of not having acted when it turned out to be useful, and make a decision according to your best estimate of how likely it is that you will benefit from following either path.
YMMV, of course, and certainly sometimes the decision will be different to others.
Please remember that my argument is not that you should always try to anticipate future requirements or over-engineer designs to cope with every hypothetical you can think of. My position is merely that you should weigh the costs of acting unnecessarily now against the costs of not having acted when it turned out to be useful, and make a decision according to your best estimate of how likely it is that you will benefit from following either path.
YMMV, of course, and certainly sometimes the decision will be different to others.