An anterior placenta in a woman with a previous c-section is something to be mindful, but not fearful, of. The placenta burrows into the endometrial lining when it implants, and if it is attached over the scar, it is slightly more likely to burrow through the scar, causing placenta accretta. It incidence of accrettas has increased astronomically over the past decade or so, as the c/s rate as increased :( Yet another reason to avoid that primary c/s.
For this pregnancy, an ultrasound near in the third trimester may be recommended to look for signs of an accretta. A known accretta significantly increases the rate of PPH, and cesarean hyesterectomies.
Additionally, if a repeat c-section is recommended for whatever reason, the surgical team would need to cut *through* the placenta to get to the baby. This increases risks for baby and you.
Certainly, telling a woman that "it's nothing to worry about" is not speaking from a place of knowledge about these important issues. Decreased fetal movement and a posterior presentation are more common, but certainly not more dangerous, things to be aware of.