Rebalancing and short-term trading fees

[Cubswin]

Someone help me out here. I currently own:

Fund A (has short-term trading fee of 1% for 30 days or less)
Fund B (has no short-tern trading fee)

I want to rebalance and contribute like this:

Fund A
Fund C
Fund D

I contribute monthly and wish to avoid short-term trading fees. I thought the ideal way to rebalance and avoid fees would be to make 100% of my next contribution to Fund B, which has no short-term fee, and then rebalance. When I go to change my allocations at fidelity I get this notice:

"Fees might be assessed to your account as a result of future transactions:

A short term trading fee of 1.00% will be assessed on any shares of FUND A you have owned 29 days or less."

I'm confused. I'm not trading fund A, I'm merely changing my allocation of future contributions, right? Why is this popping on to my screen then? Am I just having a senoir moment or is Fidelity just giving me this warning for no reason?