WRONG. For one simple reason. The default appearance and CSS values of tags has NOT ONE BLASTED THING TO DO WITH WHAT THE TAGS MEAN! And that's true even for <b> and <i>
DIV and SPAN are semantically neutral, so yes they do kind of mean the same thing, but your reasoning is way off the mark because appearance isn't what HTML tags are for. Grammar and structure is. Thus a UA -- ANY user-agent-- can try to convey that meaning regardless of device capabilities or user limitations!
If you are thinking the default appearance of ANY of your tags when writing your HTML, you are choosing all the wrong tags for all the wrong reasons. Same reason these nitwit "frameworks" with their presentational classes are incompetent trash!
A bigger flaw though is your use of the term inline-block, which is something different entirely... and confusing HTML inline/block with CSS display states. Whilst they do default to a name match, they do NOT mean the same thing.
SPAN is phrase level, it does not interrupt the flow or create pauses on screen/braille readers. It's just a neutral hook to say "this MIGHT receive some sort of style or behavior".
And yes, DIV is similar, but it's block level / structural. Screen readers, braille readers, and other such UA's will use it as a break and possibly even a landing.
Their default appearance for visual UA's having dick-all to do with it.
You also use the value inline-block which is something different entirely... so even your CSS statements are gibberish.
display:block; Defaults to full width, can have dimensions set on it.
display:inline; Shrinks to fit its content, ignores width and height, vertical padding is applied to the render stage but is ignored for height/flow calculations... unless you're in IE in which case it behaves as inline-block.
display:inline-block; Behaves as inline in shrinking to content by default, but can have width, height, and vertical padding set.
DIV and SPAN are not "inline-block" in EITHER HTML or CSS. They are block and inline respectively. Three separate things!