• <gh/ch> has the usual ach-Laut/ich-Laut allophonic contrast present in German and Middle English.
• <w> can be pronounced as [v] , since a majority of Germanic languages besides English pronounces the outcome of *w that way.
• <wh> can be pronounced as either [w] or [v], though technically speaking it should contrast with <w>, typically with the pronunication [hw] or [upside-down w]
• <th> and <dh> can be pronounced [t] and [d] in addition to [theta] and [eth]. This is the case for many L2 English speakers already.

All phonemes/graphemes not listed below are uncontroversial (e.g) every Germanic language has that kind of phoneme and writes them the same way. This includes the nasals and stops for example.

Controversial in some way:

• <w>: This is not quite as Anglo-centric as it seems, at least not for <w>. Not only is this conservative outcome in the most spoken language, but <w> is also the grapheme for [v] in German and Dutch, making it even more recognizable. The acceptable range of pronunciations should smooth over pronunciation difficulties. It is already the case that many L2 English speakers pronounce <w> as [v] anyway.
• <wh>: This is definitely somewhat Anglo-centric. It is a conservative feature that is present only in English, but *hw developed differently in different languages. It is nice that <wh> is confined to a small set of words and only as an initial sound, so it shouldn't be too impactful. The main thing is that writing the wh- words with <wh> makes reading intelligibility far greater for English speakers.
• <th> and <dh>: Perhaps overly Anglo-centric, but Icelandic has these and they are from Proto-Germanic.
• <sch>: Most Germanic languages have this sound. <sch> seems to be an unambiguous way of writing this sound, and English writes it this way sometimes from German loanwords.
• <ch>/<gh>: I can't decide between this. On the one hand, English uses <gh>. On the other hand, it uses <ch> in the word <loch> and <bach>, and German and Dutch use this sound as well.
• <j>: English loses, partly because every Germanic language except English uses it, and not only that, a most non-Germanic languages reserve <j> for [j]. Arguably more importantly is the fact that there is a correspondence between non-English [j] and English [dʒ] in many cases, such as between German "Jan" and English "John".