Glad you had a chance to get out on the water. The work could cause major issues for the fish and insects. Generally TVA uses somewhat poor judgement with their timing, if it was perfect they would do this during the colder months when temps wouldn't be an issue. They also generally leave it off way too much and let downstream flows become non existent.
I have a feeling the flows will be extremely low, temps will push the limits, and the didymo explosion could be scary. This is usually what happens during these events.
I honestly wish they would close the river during this period, do it in the colder months, or build a diversion dam so they could work and run normal flows.
One thing which will be interesting and problematic as well, is they are calling for 3"+ of rain later this week, and if they shut the river off completely silt will be a massive issue on the lower river.