Might be a coincidence.
For my case, it was for GK (both times; that is, my 6 star GK in my team performed badly on those days that the recommendations were for GKs, and also a day before, and the assistant manager also mentioned bad things about my main GK in the match reports).
But, do also take into account what some users reported earlier, where STs were not scoring or not scoring enough goals.
Also, take into account that you have a relatively overpowered team. You might have missed some rare, individual poor performances as it probably did not affect the overall performance of team significantly. Just keep an eye on it. The more observation data we get, the better it is to make a proper conclusion.