The luggage is an interesting addition.
I've been assuming this visit is for Cathy & Andy to ask the Parkers to either plan their bachelor and bachelorette parties OR propisition them for some pre-nuptial partner-swapping.
Long shot theory - they're gonna ask the Parkers to House-sit for them while they're off on a pre-wedding honeymoon.
Not a common thing but it does happen; for established couples that already live together, can't line up time off work for after the wedding date, got a time-sensitive deal on a tropical vacation but have to go now, etc.
Obviously the Parker's can't both house-sit, they have kids to look after. But if Liam pipes up with a "Well, it is closer to my office" and house-sits alone then it would remove him from the home for a while, further reducing his influence on Sophia's continued corruption.
Although, given how prominent it is in the first render and L&P's habit of misleading us, it could be a complete red herring.
Edit. Well fuck me then