Touch to replace is pretty cool but buggy in some situations. Try the following:
1) Type a word and press space or accept a suggestion
2) Touch that word again to replace
3) Select the replacement
4) Now I would expect to see the usual choice of punctuation, but instead see the same choices
5) Type a space
6) I still see the choice of replacements, and tapping on one enters a new word using the suggestions from the previous word
Weird behavior...
1) Type a word and press space or accept a suggestion
2) Touch that word again to replace
3) Select the replacement
4) Now I would expect to see the usual choice of punctuation, but instead see the same choices
5) Type a space
6) I still see the choice of replacements, and tapping on one enters a new word using the suggestions from the previous word
Weird behavior...