Once more we have an example of these being changed to those (in this instance, in the 1837 edition). This change was very likely unintended since either reading will work here. The 1908 RLDS edition restored the original these to the RLDS text (most likely by reference to 𝓟). The LDS text has retained the 1837 reading. The critical text will restore the original these.
There is another case where the 1837 typesetter may have changed these to those:
In this case, the original text read “in them days”. In his editing for the 1837 edition, Joseph Smith grammatically corrected the them to these in 𝓟, but the 1837 edition reads those. Although this may have been a typo introduced by the 1837 typesetter, it is also possible that Joseph himself changed his mind, deciding that “in those days” would work better than “in these days”. There are also two other cases where the 1837 edition introduced a switch between these and those; see under Helaman 15:3 and 3 Nephi 10:17 for discussion of those two examples.
Summary: Restore the original demonstrative these in 3 Nephi 16:10 (“if they shall do all these things”); the 1837 change to those appears to have been accidental.