How does Mains Isolation work with the ACS71020 IC?
The multiple 1 M&Omega; resistors are part of the isolation barrier between the mains and the low-voltage side of the chip. Clearance and creepage are not an issue at the pins, because the chip itself prevents the voltages on those pins from getting too far from ground potential.

The suggested layout doesn't show the resistors, but I assume that they would have to be through-hole devices so that the circuit meets clearance and creepage requirements between the two sides.