Google N-gram Corpus Counts
╭─ーーーー─┬─────────┬───────╮
│ 柊　　　 │ 510,216 │ 78.8% │
│ 疼木　　 │     117 │  0.0% │ 🡠 rK (daijs, koj)
│ 柊木　　 │   3,598 │  0.6% │ 🡠 adding (meikyo); also in the name dictionary
│ ひいらぎ │  57,662 │  8.9% │
│ ひらぎ　 │   5,488 │  0.8% │
│ ヒイラギ │  70,197 │ 10.8% │
╰─ーーーー─┴─────────┴───────╯

@@ -10,0 +11,5 @@
+<ke_inf>&rK;</ke_inf>
+</k_ele>
+<k_ele>
+<keb>柊木</keb>
+<ke_inf>&rK;</ke_inf>

Yes, the tag was put on the wrong kanji, probably during a merger.

only koj has 鮗 and it's in a note.  there's absolutely no way that those news frequency tags belong to 鮗[ひいらぎ].  i suggest putting them on 鮗[このしろ] instead.  but even there i feel like they are probably false positives.

is there any possibility that the tags belong on 柊 instead (e.g., the tags may have been moved by accident due to human error)?

@@ -6,0 +6,2 @@
+<ke_pri>news2</ke_pri>
+<ke_pri>nf38</ke_pri>
@@ -9,5 +11,0 @@
-</k_ele>
-<k_ele>
-<keb>鮗</keb>
-<ke_pri>news2</ke_pri>
-<ke_pri>nf38</ke_pri>
@@ -29,2 +26,0 @@
-<stagk>柊</stagk>
-<stagk>疼木</stagk>
@@ -37,2 +32,0 @@
-<stagk>柊</stagk>
-<stagk>疼木</stagk>
@@ -41,1 +34,3 @@
-<gloss>holly (common mistranslation)</gloss>
+<misc>&uk;</misc>
+<s_inf>common mistranslation</s_inf>
+<gloss>holly</gloss>
@@ -45,0 +40,2 @@
+<misc>&uk;</misc>
+<s_inf>also written as 鮗</s_inf>