Footnote 2 in the paper by Avram has this to say about pseudo-reduplication. 'Also called “quasi-reduplicated forms” (Bakker 2003: 40), “phonological reduplicated base form” (Miller 2003: 290), “fixed forms” or “fossilized forms” (Wellens 2003: 226). The comparative Austronesian dictionary says this about 'Quasi-reduplicates' : "Quasi-reduplicates" are those words that lack the corresponding unreduplicated forms e.g. didi 'pig, swine', nisnis 'beard'. It seems that the original unreduplicated form may have been lost within the language leaving just the reduplicated form as a sort of fossil. Note that this is not at all what serendreduplication is. It is, well, something completely different.
Now, serendreduplication may be used to motivate the idea that many things in languages may have arisen purely out of chance. I can think of so many things like that. For instance, the (Chinese) name Yao (as in Dennis Yao) is the slang word in Tamil for 'sir' or 'man' (and comes from the word 'ayya'). Pure chance that it is the case. (Think of what it would be like if a guy walked up to a Tamil speaker and told him his name is "Yao Yennaya"). And there is also the more unfortunate case involving the firm "Lund International'. The name of the firm has a somewhat funny meaning in Hindi.
But the point is that this sort of serendipity arises. And this sort of serendipity is, in fact, exactly what Buffalax of misheard lyrics fame exploits all the time. So what should we call the pairs of words and phrases that sound the same in the 'misheard lyrics'? I say let us call them 'serendhomophones'. They are words or phrases that similar to each other but it is pure serendipity that it is so. Note that the correspondence is not exact. It is just "close enough". And so, that leaves us with the minor matter of naming the phenomenon. And that is simple. This phenomenon we shall call 'serendhomophony'/'pseudohomophony'.
The term 'metametals' could also be used to describe artificial 'metals' engineered to have certain types of properties, that is, a metamaterial that is a metal. The word 'metametal' is a good example of 'serendreduplication', and is probably a better example of 'serendreduplication'/'pseudoreduplication' than 'metamathematics'.