Hair loss is
1. Exactly the type of "side effect" that people will report because they lost hair (because lots of people experience hair loss whether they are on a GLP1 or not)
2. A fairly minor side effect that wouldn't be a strong reason to not prescribe.
Pancreas issues were worried about, but those worries (so far) appear to be unfounded. https://pmc.ncbi.nlm.nih.gov/articles/PMC6382780/ is a meta-analysis of 12 studies (36k patients) over 2 years that showed no evidence of increased pacreatic issues, and https://pubmed.ncbi.nlm.nih.gov/38175642/ is a 7 year analysis of ~33k patients that also shows no increase in issues.