Depends, I doubt an absolute ruler would be very keen on giving concessions to the workers since he doesn't exactly gain anything from it, he would be forced to at some point but he would prefer not to.
Then you're thinking too simple. In every society there's multiple competing interests not some "honor amongst thieves for the rich". A Medieval King absolutely benefits from strengthening the guilds at the nobilitys expense.
Likewise an absolute monarch might find workers rights to be a useful tool against the plutocrats. It's not like he is paying the for the workplace safety measures, higher wages, days off, etc. Once passed they need to be enforced which means there'll be people on his payroll who can fine businesses or even shut them down.
To give two OTL examples from the very limited democratic UK:
The 1833 Factory Act which finally somewhat limited child labour, introduced maximum working hours, factory inspectors, etc was passed when very very few people could actually vote in the UK. Certainly not those who actually did the hard work in the mines and factories. It passed not because idealistic reformers were the majority in the UK parliament. It passed because in addition to the idealistic reformers most of the "Fat Tory Landowners" as Black Adder would call them voted for it in order to stick it to the upstart industrialists.
Likewise the repeal of the Corn Laws in 1846 happened only because a lot of Rich Capitalists who didn't give a fuck about poor people voted for it in order to screw over the Aristocratic Land Owners.
An absolute monarch - especially one who has examples like OTLs France and UK on how a rising Mercantile class will one way or the other usurp his power unless he clips their wings while he still can - has plenty of self-interested motivation to support the workers on occasion.