I can only give you a perspective from a UK regional airport - if nothing is mention or promulgated about speed then no clearance is required. I'll watch you and if I need to to keep the speed up or to slow down I'll give you a speed to fly to fit into the sequence (yup we do do sequencing at regionals!). After many years of watching I know the sorts of speeds that will usually be flown (well, certainly the relative speeds) by the common aircraft I deal with so if you plan to fly faster or slower than might be considered 'normal' it's handy if you mention it. But in all honesty it's not busy enough to really put a spanner in the works if one aircraft catches me out - and it's usually because it goes faster than I planned for - it probably means a dog-leg or a bit of late speed control. So, like I said, it helps everyone if you tell me you want to keep high speed or to slow up early.