Our 6 wo is sleeping in his cosleeper next to us in our room. I’ve noticed the past two nights that he’s moved from the middle of the bassinet to one side. He is currently being swaddled with a. blanket up to his belly button but I’m wondering if this is a sign to move to a grow suit? He’s still the facing the same time way, just made his way to the side of the bassinet.

Many babies will wriggle & change position (like you describe) at a young age.
Often this can mean that baby is soon going to be rolling.

Some babies just do not respond well to wrapping & like their arms free.
What type of swaddle are you using?
Often these babies like their arms free or like to touch their face or suck fingers, & will wriggle to get free.

Most babies will be rolling over by 4-6 months…....some earlier, some later.
This is very normal as babies grow & become stronger many babies then prefer to sleep on their tummy.
*It is important that you move him from bassinet to his cot & cease wrapping once he is rolling or attempting to roll.
*Baby needs arms free & the space of the cot to roll safely.

Red Nose also recommends modifying any wrap at 3 months to allow for arms to be free, in preparation for rolling
Modify the wrap to meet the baby’s developmental changes, e.g. arms free once ‘startle’ reflex begins to disappear which is usually around 3 months
https://rednose.org.au/article/wrapping-babies

Once he is rolling it is important to make the environment as safe as possible for this to occur.
Continue to place baby on their back to sleep.
Ensure cot mattress is firm, well-fitting & flat.
Ensure there is nothing loose or soft in the cot.
Preferable to use a sleeping bag when rolling that has appropriate size neck & arm holes.

Red Nose has the following information when baby is rolling.
Give baby extra tummy time to play when awake and supervised as this helps baby to develop stronger neck and upper body muscles which in turn enables them to roll back over.
Make sure that baby is on a firm and well-fitting mattress that is flat (not tilted or elevated).
Make sure that baby’s face and head remains uncovered (do not use lambswool, doonas, pillows, cot bumpers or soft toys)

As babies grow and develop they become very active and learn to roll around the cot.
At this time, continue to put them on the back at the start of sleep time, but let them find their own position of comfort.
By this stage it is not necessary to wake during the night to turn baby over to the back position

Do not use any devices designed to keep baby in a particular sleep position.
https://rednose.com.au/article/what-do-we-do-now-that-a-baby-has-started-to-roll-over