Absolutely - the Stock Shock was Garbage when new! Replace immediately, or Never attempt High Speed Sweepers.
I’ve Always had to retighten the new Thrust Bearings after one tank of gas.
A Worn Rear Tire will also scare you at speed.
Make only One Change at a time.
When everything is Right the bike will Handle quite Well.
You can’t defeat its Weight, or high Center of Gravity, but I can still show Squid Kiddies how its done.
Yes, I agree the shock is always pretty suspect. After stuffing around with different standard shocks for years my next job on the bike is to do a Blackbird shock mod, which will be make up an adapter leg from the shaft and bottom mount from a standard shock, with a socket to take the Blackbird shock.